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Full text of "73 Magazine (October 1974)"

AMATEUR 



$1.00 
October 1974 




SPECIAL: 

FM & REPEATERS 



FIRST 

HAM 



ALSO . 



SELECTIVE CALLING 

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magazine 

for radio amateurs 



FEATURES 



2 

3 

3 

4, t35 

6 

a 

8 

9 

10 

12 

13 

16 

17 

30 

36 

42 

128 

131 

134 

134 

17, 133, 134 

136 

137 

139 

140 

141 



Say Die W2NSD/1 
FCC Nem 
Convention C^iKiue 

FCC Boondoggling 

QSL Cornell 

Looking West 

50 MK# Band 

Repeate* Updale 

SSTV Scene 

OX 

EBC 144 Jf 

Amial 

Nanotarad 

Tube Cooking 

Ham Rjdio'i Futui e 

TV! Fix it 

Ham Help 
Conies it 
New Producu 
Murphy \ La>,\ 
Pu^le 

Tube Warranty 
Soctal Evens 
Circuus. Ore urn 



EDITOR 

Wayne Green W2NSD/1 

ASSOCIATES 

Gus WL Browning W4BPD 
Tom Difliase WB8KZD 
Terry Fqx WS44FI 
Mikefrva WBBLBP 
Dave Ingram K4TWJ 
Joe Kasser G3ZCZ/W3 
Bill Pasternak WA2HVK/6 
JohnSchylu W2EEY 
Jonathan Tara WB8D8N 
Bill Turner WA0AB I 

PRODUCTION 

Debre BoudHe&u 
Lenore DeLlguoH 

Bill Heydolph 
Biff Mahonov 
Lynn Pjnciera Frw 
Bob Sawyer 
Barbara Walker 

ADVERTISING 

Bi« Edwards VVB6B ED/ 1 
Karen Heberf 

BUSt NESS 

KnudE KeKer KV4GG/1 

CIRCULATION 

David A Behnke 
Barbara Bloc* 
Dororhy Gibson 

TRANSPORTATION 

Bill Barry 

Ted Edwards IrVlGVW 

DRAFTING 

T. M. Graham WBFKW 

Btll Morelio 

Wayne Peelei K4MVW 



CONTENTS 



20 The FCC As Seen By 

The old Rash oman bit. 
24 Introduction to Micro Transistors , . , 

Build this 6m transmitter. 
31 Build a 2m Frequency Synthesizer . . . 

Part I . . . the theory, 
37 Repeater Government Guide --...., 

Laws and by-taws 

41 The Heath HWA 202 1 ; Any Good? . . 

Reader test report — did he like it? 
43 Simple Power Supply for Digital Work 

Actually, it's complicated. 
45 Flood Emergency! 

Hams save the day, as usual, 

50 The GDO, the VOM ( the XYL 

Each has its place when repairs are called for. 

51 Selective Calling Via Repeaters 

With this touch pad decoder. 
55 How To Stop Antenna Rip-Offs 

Removable mobile vhf antennas. 
61 Two Meter Lids — Exposed! 

Not thee or me — right? 

64 Two Meters Ain't Twenty 

How to lose friends — easily, 

65 Mighty Motorola Meterer ....... 

Those SQD's are cheaper'n rice boxes, 
67 AM on Repeaters? Holy Moly! ........ 

Heresy in San Mateo. 
69 Waterpipe Antennas for 2m ■ 

Correcting alotta bum dope that's out* 

75 Is Your Deviation Wrong? 

Well, set it right — simply. 
77 Get More Zap With ThJs 2m Antenna . . , 

The wonders of the co-axial dipale. 
79 Build This Two Transistor IF Strip 

Use it with hf and vhf converters. 

86 San Francisco: A Big Moment! ........ 

Repeater history is made. 
89 Win CW Contests With Moskey 

Part II — Memory better than an elephant* 

98 You Can Tune Oscar 7 ,..,'. 

On 3 bands with one receiver! 

99 Exciting New Carbon Mikes 

High output with excellent quality. 

1 02 Kill The T VI Demon 

With this low pass filter. 

1 04 How To Say It In Ham 

Primer for XYLs. 

108 A Foreign Language! . . 

New zest for your QSOs. 

111 Make 6m Come Alive „ . • .'..>... 

With this simple p re-amp. 
1 14 Are You Wasting RF Output? 

Anode vs power output tuning, 

116 WWV Time With Any AC/DC Radio 

10/1 5 MHz with this one-tube converter. 

117 Can Your Extension Cords Start A Fire? , . * 

Handy guide to overload prevention. 

119 Prevent NCX-5 Burnout 

Simple mod and tube replacement. 

1 21 An "Invisible" Antenna That Works 

For apartment dwellers and travelers. 
1 24 Fast On The Trigger SSTV 

Automatic vertical trigger circuit. 
126 The HT-144B: Is It Really Good? ,.•..... 

Reader report on new HT kit. 
130 Cover: First Beefeater Ham . . 

May manufacture gin poles. 



.. W6EIF 



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...... W8KBC 



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.... . , . • . 



. . . W3HPX 



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WB4MYL 
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WA1GFJ 



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G3BID 



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. . . . .K3SCW 

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... WA1FBE 



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73 Magazine is published monthly by 73, Inc., Peterborough* New Hampshire 03458, Subscription rates are $7 for one 
year in North America and U.S. Zip Cade areas overseas* $8 per year elsewhere. Two years S12 and $13 overseas. Three 
years, $15, and S 16 overseas. Second class postage paid at Peterborough New Hampshire (13458 and at additional mailing 
offices. Phone: 603-924 *3tl 7 3, Microfilm edition of 73 available from thticersity Microfilms Ann Arbor Ml 48106, 
Magnetic tapes available from Science for the Blind, 332 Roch Hilt Rd,, Bala Cynwyd PA 19904. Entire contents copyright 
I 974 bv 73 Inc., Peterborough. NH 03458, 



OCTOBER 1974 



1 




JY1 VISITS CANADA 
CARF arranges special licensing 
Doug Burrill VE3CDC, the Vice- 
President of the Canadian Amateur 
Radio Federation, had his work cut 
out for him getting through yards of 
official red tape to set up things so His 
Majesty King Hussein (JY1) could get 
on the air while on his visit to Canada 
in mid-August. He did manage this 
and was able to arrange for a nice 
letter to be presented to Hussein from 
the CARF Secretary VE3CRL inform- 
ing him that this had been set up, You 
can bet that amateurs around Ottawa 
and Vancouver, the two major areas 
that JY1 would be visiting, were 
keeping their receivers warm, 

INVOLVEMENT IS CRITICAL 

In talking with FCC officials 
recently it evolved that one of the 
more serious problems facing them is 
the apathy of amateurs in providing 
feedback on proposed rules and regu- 
lations, 

Quite a bunch of proposed rule 
makings and dockets have been 
released in recent weeks and the FCC 
not unreasonably expects amateurs to 
be interested enough to send in their 
comments on them, 

For instance there was a proposal 
that the prohibition against linking 
repeaters be removed. Now this has 
been a sore point with repeater groups 
ever since the rule appeared in Docket 
18803 — not that many repeaters have 
any wish or need to link up, just that 
the prohibition didn't make any sense 
and few repeater groups felt that the 
restriction did anything but dis- 
courage experimentation and initia- 
tive. But now that the FCC has replied 
to these criticisms by offering to 
delete the restriction, repeater groups 
have almost totally ignored the whole 
matter There are over 1100 licensed 
repeaters in the country at present 
and every single one of these groups 
should move heaven and earth to 
make sure that their group sends in a 
comment on every repeater oriented 
docket and rule making — plus as 
many individual comments as 
possible. If the original and 14 copies 
is just too, too much to handle, at 
least send in a lousy post card! 

The fact is that we take a lot of 
space in 73 to print the FCC dockets 
— space that we would prefer to use 



EDITORIAL BY WAYNE GREEN 



for a couple more construction pro* 
jects — but we do it because we know 
(and you know too} that the only way 
we will get the rules we want and need 
is if we keep Washington informed on 
what we want. When we take the 
pages to print those dockets it is your 
responsibility to read them carefully 
- and further you should make 
damned sure that they are read at the 
next club meeting and discussed, com- 
plete with a letter from the club 
secretary expressing the opinion of 
the club. 

Take the Races docket which was 
published in the August issue of 73 on 
page 6. Nothing much there that your 
club would be interested in, right? I'll 
bet no one even read the docket 
through to see what was happening — 
after all, who cares what Races is 
doing? Well, fellows, the word from 
the FCC is that you darned well better 
read that docket and get yourself into 
gear, for that one is a little sleeper 
which could have a few thousand 
non-ham operators sitting there using 
our ham bands. 

This has, according to reports, 
already been happening in the Chicago 
area. Races stations have appeared 
using Races calls and been chatting 
away happily on two meter FM, 
telling objecting hams to mind their 
own business, I wonder how many 
clubs in Illinois have gone to the 
trouble to find out what their state 
has submitted to the FCC by way of 
comments on the Races docket? Are 
they aware that Illinois wants to take 
all those nice ham band frequencies 
allocated to Races and make them 
into local government bands? Are 
they aware that this is the official 
proposals of their state? That could 
mean local government use of 2m and 
75m! What does your local govern- 
ment intend to do about Races? Many 
want these valuable frequencies, but 
don't want to be bothered by having 
to have amateurs to use them. 

In September we had a bunch more 
dockets — one on special call signs for 
Extra Class licenses - one on relaxed 
logging. I assume that virtually every- 
one likes the idea of simpler logging, 
but how many have written to the 
FCC with comments? This could 
easily end up lost to us because the 
only ones who bothered to write in 
happened to be a couple of hidebound 



conservatives who think that because 
their grandfathers had to log every- 
thing, we should too. 

Also in September there was a 
docket on commemorative stations, 
one on automatic control of repeaters 
and one on crossbanding of repeaters. 
The first one of those will be of little 
interest to you or to clubs until some 
time in the future when you decide 
that it is time to put on a special event 
station - then? What can I say about 
repeater groups and FMers who griped 
about docket 18803, who fumed at 
the restrictions, and then go happily 
on their way ignoring the FCC's 
attempt to put things to rights? You 
may be sure that there will be a few 
negative votes cast on each of these 
dockets — and there is a good possi- 
bility that they will carry the day — 
just because no one else even bothered 
to send in comments. 

SSTV TAPES NEEDED 

SSTVers who work up an interest- 
ing program are asked to make a 
duplicate tape and send it to 73 
Magazine so it can be further dupli- 
cated and used for demonstrations by 
dealers and at hamfests, There is just 
too little available that is of value for 
this application - and remember, the 
more that we are able to get interest- 
ing SSTV programs shown around, the 
more SSTVers we will have, 

A demo tape is available now from 
73 for this use, but it is not as long as 
we would like, and it needs more 
interesting material - so, how about 
it? 

IOWA FURIOUS WITH FCC 

The police in Iowa have been 
getting more and more frustrated by 
the use of CB by truckers to thwart 
the speed limits and other state laws. 
Recently they got the cooperation of 
a team of FCC agents and arranged a 
mass inspection of trucks with CB 
antennas. The FCC did inspect, but 
instead of doing anything to help 
Iowa with their policing problem, all 
the FCC fellows did was hand out CB 
license applications to those truckers 
who had CB radios and no licenses. 
Iowa figures that by issuing mere 
warnings instead of taking action 
against illegal CBers is encouraging 
illegal use of the CB radios. They feel 
that truckers win ignore any agency 
that goes around saying, "Naughty, 
naughty." 

WANTED! 

A number of people are most 
anxious to find out where Keith 
Lamonica W7DXX (also known as 
Bob Keith! is located. If you hear him 
on the air (2m FM is most likely) or 
hear him announcing over your local 
radio station, please drop a line to 73 



73 MAGAZINE 



immediately, His last known where- 
abouts was in Huntsville, where he 
worked for several television stations. 
He may be in the Birmingham area — 
or almost anywhere. 

..,W2SND 




Adopted: June 1 1 , 1974 

1, Because not all remotely con- 
trolled amateur radio stations are 
additional stations, it is inappropriate 
to present the rules for remotely 
controlled stations under the undesig- 
nated headnote Operation of Addi- 
tional Stations in Part 97, Subpart D. 
For this reason, the rules for the 
operation of a remotely controlled 
station are relocated, with only minor 
editorial revision, from §97.108 to a 
new §97.88 under the undesignated 
headnote General 

2, Because this amendment relates 
to editorial revisions only, prior notice 
of rule making public procedure and 
effective date provisions are 
unnecessary, pursuant to the Admin is 
trative Procedure and Judicial Review 
provisions of 5 U.S.C. 553. 

3, Accordingly, IT IS ORDERED, 
pursuant to §§4{i), 5(d), and 303 of 
the Communications Act of 1934, as 
amended, and § 0,231 (d) of the Com- 
mission's Rules and Regulations, that 
effective June 21, 1974, Part 97 of 
the Commission Rules is amended as 
above. 

FCC 

John M. Torbet 

Executive Director 

CB RULE CHANGE 

Docket 20118, released July 31, 
proposes to change the CB rules to 
prohibit the marketing of external rf 
amplifiers capable of operating in the 
1 1 meter band; They will prohibit the 
sale, lease, offer to sell or lease, 
import or even the shipping of these 
amplifiers. It would also prohibit the 
use* 

The exception would be rf ampli- 
fiers made for amateur radio, and 
these would have to be multi-band. 

The deadline for comments on this 
Docket is September 30th, which 



seems a bit too soon. The September 
issue of 73 (presumably the other ham 
magazines) had gone to press, which 
means that the earliest issue which 
could carry this Docket would be the 
October issue. In turn this would 
mean that many amateurs who might 
like to comment upon the Docket in 
view of its restrictions on amateur rf 
amplifiers (though the restrictions are 
not particularly onerous) will be 
unable to meet the deadline. 

Docket 20119, released July 31, 
proposes changing the Part 15 (low 
power unlicensed transmitters) from 
the 11m CB band (where those little 
toy 100 mW rigs have been raising 
Cain, particularly around Christmas 
before they self-destruct a few weeks 
later) to a new berth right next to the 
6m ham band. The new channels are 
proposed for 49.9 — 50.0 MHz seg- 
ment. 

If the frequency control of future 
Part 15 rigs is no better than those of 
the past (and why should they be?) 
the 6m ops are in for a lot of garbage 
on the low end of the band. Of course 
they may never notice this since the 
bottom 100 kHz CW band is almost 



totally deserted, even during the most 
widespread band openings. There is no 
reason to expect anything but the 
cheapest of equipment to be designed 
and sold for use in this band, so the 
prospects of wandering carriers is 
high. 

Well, bright-side viewers can look 
forward to inexpensive hand trans- 
ceivers which will be easily converted 
to 6nx 

The deadline for comments on this 
one is also September 30th, 

Docket 20120, released July 31 # 
proposes some basic changes in the CB 
rules. This docket would legislate a 
changeover to sideband in five years, 
open up a bunch more channels, and 
limit CB antennas in many ways, 
including a 40 Watt power handling 
capability. 

The expansion of the band would 
add 70 sideband channels and even- 
tually result in 100 channels being 
available. Antennas would have to be 
type accepted. 

The deadline for comments on this 
docket is January 30th, which leaves a 
lot more time than has been left with 
other recent dockets. 



CONVENTION 



The report on the ARRL National 
in New York which appeared in the 
Hotline was rather critical of some 
aspects of the convention - and drew 
criticism in turn for being critical. The 
following reprint from the Pack Rats 
Cheese Bits, the bulletin of the Mt. 
Airy VHF Radio Club (a consistently 
well done paper, by the way) is not 
published here so much to support the 
Hotline view of the National conven- 
tion as to provide a valuable set of 
guidelines for the chairmen of other 
conventions, for there are some very 
good suggestions. 

A CRITIQUE ON THE 
NATIONAL 

Seven members of Penn ARC and 
myself, accompanied by WA3PZO 
drove to the ARRL National Conven- 
tion in NYC this past weekend. We 
arrived at 10:00 AM Friday morning 
staying through until Sunday at 5:00 
PM. It was a highly interesting and 
educational three day weekend. Many 
good and bad points were noted by 
our group and are enumerated below 
for your reference, followed by 
several recommendations. 

All events as listed in the program 
appeared to be well done, major hang- 
ups were not apparent It is obvious 
that the Waldorf-Astoria although one 
of the worlds finest hotels, is not well 
laid out for a large convention, with 



CRITIQUE 

miles of carpeted stairways, ptush 
endless corridors, poky elevators, and 
spotty air conditioning, all popping up 
in the wrong places. Our Ben Franklin 
for 1976 will be a much more prac- 
tical and better suited facility. 

Contest Area 

Contests were badly neglected with 
none listed at all in the official pro- 
gram. This could well be a high point 
for our 1976 convention, as they have 
been in past years. 

Seminars 

Many interesting seminars were pre- 
sented all of which appeared to be 
well prepared by knowledgeable 
speakers, however, construction 
clinics appeared to be missing. Two or 
three at least would have proven 
interesting and informative, I would 
love to see an accomplished home- 
brewer take a schematic and demon- 
strate chassis layout, round and square 

hole punching, soldering etc. Or how 
about a clinic on soldering co-ax 
fittings — hardly anyone does it 
properly. Antenna construction is 
another. We could go on and on* 

Movies/Slides 

Except for a private showing of 
these in one of the hospitality suites 
none were scheduled. These should be 
advertised for well ahead of time and 






OCTOBER 1974 



— 



•— 



set up in automatic self showing carro- 
selles. Meritorious movies could also 
be scheduled for appropriate time 
slots. Always a popular feature at 
conventions. 

Program/Booklet 

A glossy paper production with a 
misleading cover showing a non 
existent hotel bearing no relation to 
the Waldorf - almost a dead ringer for 
the Ben Franklin in Philadelphia. Con- 
tent of the program was as bad as the 
cover. Open hours of the major 
exhibits were not mentioned once. 
Consequently many of us (including 
me) got stranded Friday night with 
absolutely nothing to do and no way 
to contact several people we had 
planned on meeting. The existence of 
hospitality suites such as Murphy's 
Marauders, Long Island DX Assn. was 
likewise not mentioned. No phone 
numbers were listed for emergency, or 
even for just plain getting lost in the 
hotel. Many times it was practically 
impossible to figure out how to move 



expeditiously from seminar to 
seminar, but no one was stationed 
anywhere who could help. 

Miscellaneous Items 

1. Bulletin Boards strategically 
located in (hopefully) pairs, one for 
official releases, one for delegates per- 
sonal items - would have been help- 
fuL 

2. Convention officials should wear 
distinctive armbands, not just lapel 
pins with ribbons as the latter are 
often impossible to spot 

3. Advance distribution of certain 
information, such as floor plans, etc, 
among key delegates should be 
attempted. 

4. No attempt was made to attract 
young people. Perhaps a reduced rate 
with local advertising for Scouts in 
uniform would be appropriate. 

5. Location of all meeting rooms 
should be clearly shown in the Pro- 
gram. 

6. Alternate stairways and toilets 



should be well posted. 

7. Parking and shipping arrange- 
ments should be published well in 
advance. 

8. A sales pitch for our convention 
should be staged at the next National 
convention to attract the undecided. 
JReston, Virginia?) 

9. 34/94 special repeater on the 
roof of the Waldorf was a phenomenal 
success. Everyone who was anyone 
had an HT on his belt, and wh,enyou 
tested an exhibitors rig, you could 
hear your voice all over the hotel. HI. 
How bout it Philly? Perhaps we could 
do them one better with an operating 
station — all bands. Any volunteers? 

10. New York City was like an 
oversize regional convention, so lack- 
ing in imagination and good old con 
vention "hoopla" (Thanks to W3CL 
for the word!} that I hereby 
recommend that ARRL appoint a 
permanent national (volunteer) Con- 
vention Chairman to breathe a little 
continuity into ARRL sanctioned 
national conventions. 



< 







I insist th t you print tv 



IRS 



My son, John Goodwin WA5ZEK, 
is a subscriber to your magazine. Since 
1954, I have been involved in the 
preparation of Federal and State 
Income Taxes, In that time, income 
tax has grown from nuisance to 
tyrannical proportions. The people for 
whom I prepare taxes are primarily 
working people, wage earners. Income 
tax is withheld from their wages along 
with FICA. In our area, a working 
couple can earn from $10,000,00 to 
818,000,00. It is alarming the total 
taxes withheld from their wages and I 
grow more angry each tax season, and 
have cast about as to how I could 
encourage people to object. Most 
people are mortally afraid of the I RS 
as you have pointed out 

It never occurred to me to read 
"73" for tax information, John called 
my attention to your articles which I 
read with eagerness and approval I am 

eager to participate in anyway to 
bring about tax reform, and am open 
to any suggestions you have to offer 
Primarily, the people who feel the 
same as you and I lack the leadership 
to act. If you can contact people in 
my area who are able to assume 
leadership and bring about organiza- 
tion for concerted action, it would be 
a step in the right direction. Our first 



major objective should be removal 
from office of our own Wilbur Mills, 
who, as you know, is chairman of the 
powerful Ways and Means Committee. 
He is up for election this Fall. Since 
we were able to topple our Rhodes 
Scholar in the primaries, it is not too 
far fetched to think we might displace 
our Mr. Mills. 

The time for action was yesterday; 
keep the good work going. 

Bern ice Goodwin 
Fort Smith, Arkansas 

TAPES GREAT 

I have received your 4 code tapes. 
They are the best yet I'm using mine 
for brush-up and they sure fill the bill. 
I now feel I can build up my speed. 

C A, Apland W7ZJC 
Lynnwood WA 98036 

CASSETTES GREAT 

I have your cassette recorder and it 
works every bit as well as my 
daughter's, which cost several times 
more, I still think 73 is the best place 
to look for anything you might want 
for a ham. 

Edward Seidel, Jr. WA8HGS 

DO IT YOURSELF 

Bill Hoisington's article "An Auto- 
matic and Phone Monitor Control 
System" in the February 1974 issue 



of 73 really sparked my imagination* 
As a result, I would like to propose 
another project which I am sure 
would find universal appeal among 
your readers. 

My do-it-yourself construction 
article involves a small supercon- 
ducting coil which can be inserted 
into the electric power meter through 
the short piece of large conduit 
between the power meter and the 
circuit breaker box. Whenever the 
amateur station is transmitting, a 
broadband detector turns on a circuit 
which applies power to the supercon* 
ducting coil, This produces a strong 
magnetic field which opposes the field 
inside the motor of the power meter 
and stops the meter, A detector cir- 
cuit, using field effect transistors, 
measures the amount of current being 
delivered by the power meter and a 
control circuit adjusts the magnetic 
field to just the right amount to stop 
the meter. The superconducting coil 
takes quite a large amount of power, 
but this doesn't really matter since the 
meter is stopped anyway. Of course, I 
will absolve the 73 Magazine, its 
editor and myself of any responsi 
bility by inserting a warning, near the 
end of the article, that the power 
company might get a little upset if the 
meter is stopped when the meter 
reader happens to come around. 

Perhaps this article will spark some 
other amateur into thinking up a way 
to use amateur radio to stop the 
natural gas meter. This will be a little 
more difficult since this meter does 
not work on electricity, but some 
smart ham will surely come up with 
the answer. From there it would be an 
easy step to make a unit to work from 
a mobile rig to stop the meter of a 
self-service gasoline pump after you 
have pumped in the first five gallons. 

Just think how proud 73 Magazine 



73 MAGAZINE 



could be for publishing detailed 
instructions on how to use amateur 
radio to save its readers thousands of 
doHars which would otherwise have to 
be paid to these giant industries. 

I am awaiting instructions on how 
to submit the manuscript. 

James E. Dal ley W0NAP 

This is fust the sort of innovative 
engineering amateurs have been noted 
for down through the years. Yet, one 
wonders at your lack of creative 
imagineering in this case — why not go 
alt the way and run that power meter 
backward so you can get a monthly 
check from the power company to 
help you buy a little more ham gear? 
Doubtless there would eventually be 
some questions raised, but these 
would be easily brushed off by the 
simple explanation that you are 
merely converting all that radio 
energy you attract with your antenna 
back into the power fines and thus 
conserving energy, What could be 
more American?, . .erf. 

FAN MAIL 

For years you have subjected 
readers of 73 Magazine to your 
paranoid accounts of your mistreat- 
ment at the hands of various parties. 
Most recently, your principal tormen- 
tor has been the IRS. And everyone 
knows how they use their Gestapo 
tactics to pursue and persecute the 
pure of heart! 

It has been difficult for me, and I'm 
sure many other readers, to under 
stand why you have always been the 
innocent victim of such unwarranted 
attacks. We have also wondered why 
you think your personal problems 
have any place in an Amateur Radio 
journal. 

But now that you have been tried 
in a Federal court and found guilty, 
maybe all this will change. "Guilty on 
twelve counts of tax evasion for sign- 
ing false returns/' the jury said, Not 
the IRS, nor the FCC nor the ARRL 
nor the Gestapo. No, Wayne, this was 
the verdict of 12 good, old Yankee 
Granite-Staters down Concord way. 

If and when you get out of jail why 
don't you apply for a First District 
call, like all other New Hampshire 
residents, confine your efforts to 
putting out a decent magazine and 
spend a little time with a good doctor 
to help clear your mind. 

You know, Wayne, all your 
supposed enemies don't really hate 
you. This is another of your delusions. 
The truth is that most of us just feel 
sorry for you and wish that you had 
taken up fishing or music. With 
friends like you, Amateur Radio 
doesn't need enemies! 

John Naylor K6BR 

485 Pullman Road 

Hillsborough CA 94010 

GOOD WORK 

Keep up the good work - Ham 
Radio needs you more than ever — 

Rich W9JS 
Oregon Wl 53575 



CODE TAPE 

I want you to know that with the 
help of your code course (5WPM) I 
passed my code test with only one 
wrong letter, A C came out N N, I 
owe it to you and that code tape. . . 
I'll recommend that tape to anyone 
that want's to get their Novice ticket. 

I also say let's send Wayne Green to 
Washington as our Amateur Radio 
Lobbyist. We need you, 

Marvin R. Bittner 
Jacksonville KY 

BOOKS 

Serious, qualified, intelligent hams 
interested in vital fundamentals of life 
should read the "Fields of Life" by 
Dr. Harold S. Burr, Ballantine paper- 
back 23559 $1.50 and/or "Design for 
Destiny" by Ed. W, Russell, Ballantine 
23405 $1,25 and then develop suit- 
able direct current amplifiers that are 
stable so that these Fields of Life can 
be measured in millivolts with an 
extremely high input resistance. 

Applications are in family planning 
and as an indicator of disease. It gets 
down to what really makes us tick and 
where we go from here. From 
Ballantine Books Inc., 201 E. 50th 
St., NYC 10022 plus two bits postage 
per order. 

Charles A Moore XE1CMB 

CANADIAN OPERATION 

Why leave Amateur Radio behind 
when you go to visit Canada this year? 

Getting a reciprocal license is easy 
to do. Send a letter for application to: 
Department of Communications, 55 
St. Clair Avenue East, Toronto 290 
Ontario, Canada. Give them your 
name, address and class of license. 
You'll get fast action. 

Leo WA1HSO 

THOUGHTS ON LICENSING 

I've been thinking out licensing 
changes for hams ever since you dis- 
cussed the question in July '74 issue 
of 73. 

When you analyze the reason for 
existence of the spectrum the ham 
allocations you know damned well 
that hobbyists couldn't hold such an 
asset by themselves. I keep recalling 
what Bud long said in a Seattle talk 
years ago, "We couldn't hold our 
bands 5 minutes by ourselves — 
they're reserved for military emer- 
gency use and we simply occupy them 
until they're required/' I'm sure that's 
correct, although I've never seen the 
statement in print. 

Parenthetically, reflection on that 
statement amuses the hell out of me 
when I see how seriously some hams 
take ourselves and our hobby. Picon, 

indeed! 

Well, to go on. That being the case 
that we're only keeping the house 
dusted until the owner returns, it 
seems obvious to me that the military 
wouldn't want the ham bands 
tenanted by a huge group such as sits 
on the citizens band - they'd simply 



be too large and too strong politically 
to dislodge easily when the bands are 
required in an emergency. 

So — the present licensing require- 
ments keep the bands fairly active, 
but not over active nor politically 
strong, and most hams have a con* 
scious desire to do the right thing for 
others, and I'm sure very few would 
operate illegally if the military needed 
the bands back. So maybe we ought 
to leave the licensing system the way 
it is with only minor changes. 

Of the minor changes I think incen- 
tive licensing is foolish. It reflects 
more of the 'taking ourselves too 
seriously ' attitude. And maybe the 
higher frequencies should have less 
vigorous code requirements. 

John W7SCU 

TWO METERS 

First of all, thank you for the 
subscription/books to be used at our 
hamfest in August. 

I know what I am about to say has 
been said before, but it seems to need 
repeating again, and again, and 
again. . . Those who operate 2 meter 
FM continually mess up on proper 
identification, operation, etc, etc. 

The Ten Commandments of Two 
Meters 

I. Thou shalt not make unidentified 
transmissions (Le. ( keying a repeater 
just to see if you are making it). 

II. Thou shalt not pick up another's 
transmission without a two second 
pause (quit tail gating - breakers may 
need the repeater for an emergency). 

III. Thou shalt always include the 
proper region number when mobile or 
portable (i.e., mobile two; portable 
five). 

IV. Thou shalt identify correctly 
(i.e., the other guy's call and then 
your call — and only once every 10 
minutes). 

V. Thou shalt support thy own 
repeater for thy usage (no one likes a 
freeloader - be a supporter). 

VI. Thou shalt not hog or abuse 
another's repeater when visiting in 
another's area (you are usually wel- 
come, but be a listener more than a 
user). 

VII. Thou shalt not mimmick the 
repeater's identifier (one need not give 
the repeater's call or frequencies when 
listening rpt. or clear rpt. is suffi- 
cient), 

VIII. Thou shalt not time-out a 
repeater (no one likes a gabber — it is 
unnecessary, rude, and ties up a 
repeater for others — go back to 80 if 
you must have "gal lopping gums"). 

IX. Thou shalt watch thy deviation 
(some machines do only accept 5 
kHz). 

X. Thou shalt watch thy frequency 
(check your jap -track and clegg once a 
month and keep it working within a 
kHz or so). 

There are many more, but these are 
the real problems - the ones that 
drive control stations "bananas"!!! 

Ronald W. Perry WA2CGA 
Trustee WR2ABB/W2CVT/WA2MRG 

Cont'd on p. f3S 



OCTOBER 1974 






FCC. BOONDOGGLING 



F. c. a. 

w**ianr* w& riootfecf yon 1* 

Submitted by 

W. H, Solfermoser KflDVI 

1905 West Lake Street 

Ft, Collins CO 80521 

The following story contains my 
comments concerning my attempts, as 
the Trustee of the Northern Colorado 
Amateu r Commu nications Assoc ia- 
tion. Incorporated (NCACA), to 
obtain an amateur repeater license for 
NCACA in accordance with the 
newest Federal Communications 
Commission {FCC) Rules, 

The NCACA was granted an 
amateur repeater license with the call 
letters WA0VVX on November 24, 
1 971 ■ Operation of the repeater began 
on December 23, I971. 

In 1972 the FCC began promul- 
gating new repeater rules as a result of 
the Docket 18803. Three definite 
deadlines were established by the 
FCC: 

1. October 17, 1972 - date by 
which all existing repeater stations 
were required to meet the new rules* 
requirements to the best of their 
ability* 

2. April 30, 1973 - date by which 
all existing repeater stations were 
required to submit new applications 
for new licenses in accordance with 
the new rules. 

3* June 30, 1973 - date by which 
all existing repeater stations were 
required to go off the air if new 
licenses were not obtained. (This 
deadline has been extended J 

The NCACA submitted its applica- 
tion for a new repeater station license 
on April 27, 1973, The application 
described the existing operation of 
WAflVVX as modified to conform 
with the new FCC rules. It was the 
belief of the NCACA that the applica- 
tion outlined operation which was in 
full compliance with the letter, and 
the intent, of the FCC Rules, 

The NCACA application was pro- 
cessed by, and rejected by, Mr, Robert 
Kite of the Washington FCC office. 

The notes which accompanied the 
rejection led me to believe that the 
application may not have been studied 
in detail. Some questions asked by Mr 

Ed Note: Despite some glitches such as 
this, the FCC has managed to license 
some 1100 repeaters! Much bravo to 
Gary Hcndrickson W3DTN, repeater 
operator, for joining the FCC and getting 
the work done. 



Kite were answered within the appli- 
cation. Some suggestions given by Mr. 
Kite for modifying the application 
appeared, to me, to be more nearly 
personal interpretations than official 
interpretations. 

For example: Mr. Kite stated that 
amateur repeater Control Stations 
should be equipped to self-identify in 
Morse code at a speed of not less than 
twenty words per minute to make 
unauthorized determination of the 
Control Station's identity difficult. 
While I appreciate his concern for 
maintaining control link security, I 
find it necessary to make at least three 
observations: 

1 . The identity of a Control Station 
need not be as secure as the control 
coding of the Control Station. Any- 
one haviny the ability to listen on the 
control frequency might reasonably 
be expected to have the ability to 
employ fairly elementary recording- 
and-playback techniques to determine 
the content of Morse code at any 
transmitted speed. Also, it appears 
rather inconsistent to attempt to hide 
the identity of a Control Station when 
transmitting, but to require the 
posting of Control Station data at the 
repeater site, 

2. The FCC Rules make no mention 
of such specific identification require- 
ments. (Identification of amateur 
radio stations by amateurs has been 
with the intent of easy identification 
by the listener, historically.) 

3. Although I have made a point of 
discussing the repeater application 
situation with every other amateur I, 
have met, I have yet to find anyone 
who considered 20-wpm identifica- 
tion, who made that a part of his 
application, who was rejected because 
of his failure to include it. 

Mr. Kite stated in his rejection 
notice that the NCACA had thirty 
days in which to re submit the appli- 
cation without losing its place in the 
FCC queue. 

The application was modified 
extensively in order to satisfy Mr. 
Kite's requests, item-by-item, and was 
mailed to the FCC on June 18, 1973 
— within the thirty day period. 

The NCACA, as an organization, 
and the Board of Directors, as 
individuals, have repeatedly expressed 
publicly their intent to operate 
NCACA stations in such a manner as 
to guarantee full compliance with the 
letter and spirit of the law, and to set 
an example of such operation to any 
amateur which might come into con- 
tact with NCACA, Therefore, after 
much discussion of the new repeater 
rules and the comments in the rejec- 
tion notice, it was decided that we 
would rather shut down the repeater 
in view of a possible discrepancy in 
our interpretation of the FCC Rules 



and Mr. Kite's. It should be stated, 
however, that at no time have we 
believed that any of the actual, or 
proposed, operation of the WA0VVX 
repeater was in conflict with the FCC 
Rules' letter or intent or spirit. 

With great reluctance, WA0VVX 
was removed from operation when the 
June 30, 1973 deadline arrived. 

Knowing that the FCC was 
undoubtedly swamped with repeater 
applications, and having faith that the 
applications would be processed as 
expeditiously as possible, we remained 
off the air without bothering the FCC 
for quite some time* 

On August 31, 1973 I called Mr. 
Kite, I told him I did not wish to seek 
special treatment, but that I wished to 
find out whether our application had 
been processed, or get an estimate as 
to when it might be processed. Mr, 
Kite informed me that he was no 
longer involved in processing the 
repeater applications; he had been 
loaned to that area only during the 
rushed period when our application 
had originally arrived. 

Mr, Kite appeared to remember our 
application and stated that it would 
be processed "in due course" by Mr. 
Ferraro. He cautioned me that Mr. 
Ferraro would not be able to discuss it 
with me. He defined "due course" to 
mean approximately one to two 
months. He suggested that if I had not 
received any word concerning the 
application within that time period, it 
might be appropriate to call Mr. 
Ferraro at that time* 

I told Mr. Kite that there was one 
other aspect of the NCACA applica- 
tion I was concerned about: two of 
the Control Station applications in the 
repeater system application were for 
licenses which expired during the 
month of August. I was told that the 
FCC Rules were explicit in stating 
that one may operate beyond the 
stated expiration date provided that 
"timely application for renewal had 
been made to the FCC" and that this 
requirement had been met. 

Referring back to the repeater 
application, Mr, Kite did not wish to 
discuss any of the particulars of the 
application nor did he wish to discuss 
any of the points for which he had 
rejected it earlier. My impression was 
that he was relieved to be no longer 
involved with processing repeater 
applications* 

After waiting several weeks, I called 
Mr. Ferraro on the morning of 
November 13, 1973. I told him that I 
did not wish to seek special treatment, 
but that I was becoming concerned 
that our application was lost and 
might, therefore, never get looked at, 
I also told him that my concern was 
deepened by the fact that we, as 
NCACA, had chosen to go off the air 



73 MAGAZINE 




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• 



rather than be, or even appear to be, 
in violation of the FCC Rules. 

Mr. Ferraro agreed to look for the 
file. After several minutes he returned 
to the phone to state that he could 
not find the file. He suggested that 
perhaps I should re-submit an entirely 
new application since it was ''probable 
that the application had been lost in 
the mails/' I informed him that I had 
in my possession the postal receipt 
stating that the application had been 
received by the FCC on June 20, 
1 973. He then had me talk with Cathy 
Adams who is, apparently , a recording 
secretary. She agreed to look for the 
file, but came back to the phone later 
to say that she could not find it and 
that she would call later that day. 

She did call late in the afternoon to 
say that she still could not find it; that 
she had the Gettysburg office looking 
for it also; that she would continue 
looking and would call me the next 
day. 

Cathy called the next day 
(November 14, 1973) and said she had 
found it. She said she was not per- 
mitted to make an estimate as to 
when it might get looked at, but that I 
could talk with Mr- Ferraro about 
that 

Mr, Ferraro said he was not per- 
mitted to make estimates, but that it 
would surely be fooked at during the 
month of November. I stressed again 
that we at NCACA were off the air 
waiting for a decision* 

On December 27, 1973 I called Mr. 
Ferraro, He did not appear to recall 
having ever talked to me before. I read 
to him extensively from my notes 
made during the telephone talks of 



November 13th and 14th. He agreed 
to look for the application and to call 
me during the first week of 1974. No 
call was ever received. 

In mid January 1974 delegates 
from the Colorado Council of 
Amateur Radio Clubs, Inc., on behalf 
of the more than twenty amateur 
radio clubs and repeater groups they 
represent went to Washington, D,C. 
where they expressed their views con- 
cerning the incompetent actions of 
the FCC in regards to amateur radio 
repeater licensing. 

The meeting lasted two hours. 
There was an ARRL representative 
present along with thirteen amateur 
representatives. Commissioners, Lee, 
Reed, Burch, Hooks, and Wiley were 
present as was most of the necessary 
FCC staff. Almost as in anticipation 
of this meeting the FCC had already 
released an order relaxing certain ama- 
teur repeater rules. This meeting 
seemed to bring about fast action for 
the Northern Colorado Amateur 
Communications Association, Inc. 
After almost eight months of waiting 
we received the call WR0ADD. 

However this was only a good start. 
Even though those certain repeater 
rules were relaxed our application was 
predicated on the more stringent 
interpretations of the FCC staff 
earlier. 

As of August 1, 1974 NCACA is 
still trying to comply with the letter 
and spirit of the law before placing its 
repeater on the air, We haven't 
succeeded, yet! 

Clyde E. Glass 

Trustee, NCACA 



OSL CONTEST 



DARC 



D 
A 

1 

M 
K 




B11 

Mike Kau! DA1MK wins the one year subscription this month with this 
striking woodcut of his home town, Nurnberg, Germany, Keep sending your 
entries to 73 Magazine, Peterborough, NH 03458, 



i< 




^@@kim§ 



BUI Pasternak WA2HVK/6 
14732 Bfythe Street #17 
Panorama City CA 91402 

This is getting to be an expensive 
habit. Here I am again, "flying the 
friendly skies of United/' heading 
West. I've been hack in the "Big City" 
the past week and a half for a very 
special event. About 72 hours ago, my 
brother Bob and his new bride Rose 
vowed everlasting love to one another 
and began their married life together. 
This was one event that I could not 
miss, therefore, the trek 3,000 miles 
east. It was a beautiful wedding, but 
now I am heading back to the place 
where I belong. More important back 
to Sharon, the person whom I belong 
with. Its been a long week and a half, 
but a good one. More about the trip 
later, but for now, let's talk about the 
latest addition to the LA two meter 
FM scene; an open autopatch 
repeater. 

Credit for WR6ACK must be given 
to its builder Doug Andrews K6VGH, 
Though ACK, which operates 147.93 
in, 147,33 out was designed primarily 
to cover the West Los Angeles area, I 
have been told that stations as far 
away as San Diego have been able to 
make it into the machine, ACK is a 
split site operation with the receiver 
located atop Mar Vista Hill and the 
transmitter in Santa Monica atop the 
General Telephone Building. This 
combination seems to give good 
coverage to its prime intended 
coverage area. The autopatch facility 
is intended for general use with but 
two built-in restrictions. A "dial 
restrictor" limits the system to non- 
toll type calls and if you are long 
winded, thereby exceeding the three 
minute timer, your call will be 
terminated for you, The only other 
rule is the one that applies to all 
Amateur Autopatch Systems. Under 
no circumstances is the system to be 
used to conduct business of any type. 
In plain English that means its fine to 
make any kind of personal calls you 
wish, but calling your office for 
messages from your secretary is a 
strict no no! 

In your editors opinion, WR6ACK 
is more than just another repeater, 
one having autopatch facility. I kind 
of view it as an experiment to see if 
such a system can survive in an urban 



8 



73 MAGAZINE 



area the size of Los Angeles. If every- 
one shows cooperation and abides by 
the rules other such systems might 
eventually get put on the air. On the 
other hand, if the autopatch privilege 
is abused; if those that use the 
machine don't support it, it might 
have to go away. Putting an open 
autopatch on two meters is a big risk 
here in LA, but someone has to be 
first. My congratulations to Doug for 
being #1. 

Mention "Star Trek" and you get 
more mail than you can hope to 
answer in a dog's age. That's what 
happened soon after the July column 
came out. No, I have no idea if Star 
Trek will ever be revived as a new 
series, but I wouldn't mind seeing it 
happen. From your letters I can 
assume I am not alone, but realisti- 
cally, I seriously doubt if this will ever 
happen. Ah, but those reruns were 
great till KCOP took them off the air. 
Must have seen each one fifty times or 
more. Gene Roddenbery and his staff 
were truly people ahead of their time. 

KPFK's "Hour 25" on the other 
hand is "live and well" here in Los 
Angeles, every Friday evening at 11 
PM Pacific time. Unfortunately, to 
those of you who asked, Hour 25 is 
heard only in the area covered by 
KPFK's 110,000 watt ERP signal, 
eminating from atop Mt. Wilson, 
(Remember that picture I ran some 
months ago of WR6ABE's new 
antenna installation? The antennas 
just below ABE's Stationmaster are 
those of KPFK.) This three hour 
program, conceived and produced by 
Mike Hodel who acts as co-host along 
with Cathy Calkin and John Henry 
Thong (Mitchell Harding's alter ego 
after passing through his Universal 
Rotator) is to my knowledge the only 



show of its type anywhere in the 
country; a program devoted exclu- 
sively to the world of Science Fiction 
or scifi (pronounced skif-feK This is 
made possible by virtue of KPFK 
being a non-commercial, listener spon- 
sored station thereby negating the 
need for commemciafs and the people 
that pay for them. There are no 
promo's heard during Hour 25 or any 
other KPFK program for that matter. 
No offense to the big three in broad- 
casting, but I prefer my programs that 
way. 

On a typical evening with Hour 25 
you might hear a live interview with 
such notables in the scifi world as 
Theodore Sturgon or Harlan Ellisson 
followed by open telephones so that 
the audience can take part in the 
interview process. This might be pro- 
ceeded or followed by reports on scifi 
conventions throughout the country 
and the program usually concludes 
with a taped reading of a piece of scifi 
work. The open telephone technique 
is also used to permit the audience 
and the hosts to discuss just about any 
aspect of scifi that you can think of, 
that in itself is making for an interest- 
ing program, PS — That should have 
been "EGUICON" rather than 
ECLICON. 

I found out about Hour 25 while 
interviewing Mike Hodel for a future 
73 article I am writing on Pacifica 
Radio and freefy admit that I have 
been hooked on it ever since. To those 
of you scifi buffs that might be here 
in LA some Friday evening and are 
tuning your FM broadcast radio 
around 90.7 when you hear some 
strange music followed by an eccoey 
voice saying "This is Hour 25, the 
science fiction — science fantasy pro* 
gram/' stop tuning. You have just 






Bill Turner WA0ABI 
Five Chestnut Court 
St Peters MO 63376 

WB40SN, who finally worked 
W7UBI, Idaho for state number 47 f 
also mentions working TI2N A, TI2HL 
and TG9KJ* Joe says in part "TG9KJ 
has been putting in a nice signal 
running 10W into a 6 element at 85 
feet If you hear TI2NA's beacon, also 
look for Luis around 50.075. He is 
usually on CW and sometimes AM. 
QSLs for TG9KJ go to P.O. Box 1 15, 
Guatamala City, and don't forget an 
IRC or two." 

Have had some correspondence 
with TI2NA which clears up the situa- 
tion there. The beacon runs 40W to a 
dipole radiating North-South on a 24 
hour basis. Erik originally intended 



listening on 50.250 but discovered no 
problem on 50.150. He says "I am 
sure you will get lots of reports that 
the beacon has been heard but my 
receiver on 50.150 fixed is not that 
sensitive and I have the problem that 



entered the world of Hour 25. 

To my many friends in the metro- 
New York area, it was great to see so 
many of you and especially those of 
you at the LIMARC meeting, Though 
the evening was hot and humid, and 
this was my first time as a guest 
speaker anywhere. The people that 
make up the Long Island Mobil Ama- 
teur Radio Club were a fantastic 
audience and went out of their way to 
make me feel at ease. I sincerely hope 
that you enjoyed my presentation and 
films as much as I enjoyed presenting 
them. For me, it will bean evening to 
remember. Special thanks to Bob 
Reed WB2DIN and Lou Belsky 
K2VMR for handling all the arrange- 
ments, providing transportation and 
for that great corned beef on rye. One 
final and very special thank you to 
Myrt Billings W2BIV for some help of 
a type that only he could give. It was 
a good trip, but this 747 wilt be 
landing in a few minutes and I will be 
home. LA may be a great big freeway, 
but it's good to see the I -405 again. 

Finally, just as I was about to wind 
"LW" u for this month, I spoke with 
Capt Dick McKay K6VGP and 
learned that he had submitted to the 
FCC a petition for rulemaking to 
permit fully automatic remote control 
over all repeaters. Needless to say, 
that this petition should it be adopted 
by the powers that be in Washington 
would be the kind of step in the right 
direction that is necessary to further 
stimulate the growth of repeater 
systems throughout the country. 
Therefore, we at LW fully support the 
work that Dick is doing on behalf of 
all amateurs and sincerely hope that 
the FCC will adopt his petition. Next 
month we will discuss this petition in 
greater detail. . . .WA2HVK/6 



if the station is off frequency it is 
unintelligible but that will advise me 
that there is an opening/' Erik also 
says "TI2HL (formerly OA4C) is in 
Costa Rica and active now on 50 
MHz. His prime frequency is 50,110 




TI2NA, the highlight of the 6 meter season. Erik works all bands from 160 through 432. 
You will most often find him on 50.1 50 or 28.600. 



OCTOBER 1974 



9 



■ 




MMjpd&to 



Revision of Recently Published Repeater Atlas 



INDIANA 

WR9ACI Anderson 

WR9ADJ Bloomington 

WR9AB0 Evansville 

K90ET Ft, Wayne 

WR9A0I Ft, Wayne 

WR9ACJ Ft Wayne 

WR9ACU Indianapolis 

WR9ACZ Lafayette 

WR9ACX Marion 

WR9AD0 Michigan City 

WR9AB0 Mtincie 

K9FAP So. Bend 
So. 



IOWA 

WRIAEH 

WAIVWI 

WILAC 

KflGVP 

WRIAEB 

WRI 

WIDYS 

WRIACF 

KANSAS 

WilPB 

WRIADH 

WRIABT 

WA8VVB 

WRI 

WRflAEI 

WRflABJ 

WRflABV 

WRIACW 

WRIACI 



Cedar Rapids 
Cedar Rapids 
Burlington 
C re ston 
Davenport 
Davenport 
Marshaltown 
Spencer 



6.22-6 82 

6.046.64 

52.920^2.575 

6.31 6 91 

6.16 6.76 

6.286.88 

449.8-444.9 

6.28-6.88 

6.16-6.76 

6,19-6.79 

T1.8 6,37-6.87 

6,13 6.73 

6.346,94- 

7.99-7.39 



TJLO 6.1 6-6 76 
7.007.60 

6.19-6,79 
6.1 M. 79 
6.04-6.64 
6.28-6.88 
G. 28 6.88 
6 22-6,82 



Hutchinson 
Kansas City 
Kansas City 
Kansas City 
Kansas City 
Kansas City 
Kansas City {RACES} 
Kansas City 
Norton 
Plainsville 



KENTUCKY 

WR4AET Paducah 

WA4YZY Ptnevtlle 

LOUISIANA 

WR5ACN Alexandria 

WR5 New Orleans 

W65FXF Ruston 

MAINE 

WRI ADS Mt, Brickfield 

MARYLAND 

WR3 Baltimore 

WR3ABQ Baltrmore 

WRE Cambridge 

WR3ABL Frederick 

WR3ABM Gaithersburg 

WR3ABT Hngerstown 

WA3DZD Harmans 

WA3SFJ Havre de Grace 

WR3ACL SevernaParfc 

WR3ACK Silver Spring 

WR3ABW Silver Spring 

WA38MM Washington O.C. 

WA3PVP Wheaton 



WA3BMM Wheaton 



6.226.82 
6.1 3^.73 

6,1 9-6.79 
6,37-6,97 
7.93-7.33 
6.34-6.94 
5.6657.21 
52.88 52.525 
6.34-6.94 
6.28-6.68 



6 16-6.76 
6.226,82 



6,346.94 
6.01-6.61 
6.34-6.94 



6.2B6.B8 



7,847,24 

6.07-6.67 

444.36449.35 

6.4^7.00 

6.13 6.73 

6.046.64 

6.34-6.94 

6.16-6.76 

444.10-449.10 

B.2*6.85 

6.10-670 

448.00-449.00 

444.00-449.00 

6.25*6. B5 

53.2552.68 

6.07-6.67 

223.30V224.30 

448.30-449.30 

S3.255Z.68 



MASSACHUSETTS 

WRtACP Agavvam 

WR1ACB Bellmgham 

W1 UQ Brookline 

WRI A DC Fall River 

WR1ABI Fall Rivet 

WRI Falmouth 

WR1ABK Foxboro 

WR1A8Z Holliston 



WR1ABX 

K1FFK 

WR1AOU 

WA1KFZ 

WR1ABW 

WR1ADC 

WRI 

WR1AB0 



Holynke (Ml. Tom) 
Ml. Greylock 
Mt. Lincoln 

No. Adams 

Somerset 

Somerset 

Springfield 

Worcester 



6.407.00 

7.66706 

CLOSED 

6.437.42 

52.01 52.70 

6.19-6.79 

6.25-6.85 

6.355*6.955 

53.64-53.04 

6.3856.985 

442.00-447.20 

22 30 22.90 

6.346.94 

6316,91 

6.13-6,73 

643-7.03 

44Z7544175 

6.43 7.42 

6.16676 

6.37-6.97 

53 72 53,12 



MICHIGAN 

WR8AEC 

WR8ADF 

W6IQ2 

WR8ABN 

WR8ACN 

WR8ADJ 



Birmingham 

Darks ton 

Crystal Falls 

Detroit 

Grand Rapids PL 

Holland 



WR8ABK Jackson 
WR8ABI Kalamazoo 
WB8CQM Lansing 



WR8 

WB8CRQ 

WB8CRQ 

WRBAAA 

WRB 

WB8FNM 

W8B8RA 

WR8ACS 

WR8 

WR8 

W8FGB 

WR8ACY 



Lansing 
Ludington 
Manistee 
Mil ford 

Mount Clemens 
Mount Clemens 
Owosso 
Rochester 
Sault Ste Marie 
Traverse City 
T re nary 
Whitmore Lake 



CLOSED 

6.25-6.85 

52. 7^52. 525 

449,00444.00 
T2.15 6.16 6.76 
6.2B-6.8B 
6.16-6.76 
6.1M.7A 
6.34-6.94 
6.22-6.28 
7,81-7.21 
6.34-6.94 
6.1 94.79 
6,10-6*79 
6.07-6.67 

444.90449.90 

449.3044110 
7.697.07 

448.7*443.75 
6.25-6.85 
6.16-6.76 
6.07667 



MINNESOTA 

WlGKO Oufuth 

WRIACN Faribault 

W2NSD 

WR0ADP Marshall 

WRIADY Minneapolis Si. Paul 

WRIADT Minneapolrs-St. Paul 

WRIAFG Minneapolis Tl 

WRI Minneapolrs-St. Paul 

WRIADM Minneapolis St Paul 

W8I8ZC Minneapolis St Paul 

MISSISSIPPI 

W5CSH Crystal Spring 
WR5ADC Pascagoula 
WR5 Vicfcsburg 

MISSOURI 

WRI Belton 

WR7ADY Billings 
WRI Columbia 



6.16*6.76 

6.19 6.79 
7.757.15 
6.16 6.76 
6.2^6.85 
6.076.67 

B 7.7*7.15 
6.16 6.76 
7.697,09 

448.7*443.75 



6.22-6.82 
6.28-6.88 
6346,94 



172-7.12 
8.346.94 
6.01-6.61 



WRI 

WRI 

WRIABT 

WRIAEI 

WAIVVB 

WRIABJ 

WRIABV 

WRI 

WRIACC 

WRIAOV 

WRIAOB 

WIEEE 



House Springs 
Jefferson City 
Kansas City 
Kansas City 
Kansas City 
Kansas City (RACES) 
Kansas City 
Kansas City 
Si Louis 
St. Louis 
St Louis 
RolU 



NEBRASKA 

WRIACZ Scottsbluff 
WRIAEA Columbus 

NEVADA 

WR7ABB Las Vegas 
WR7ABI Reno 



NEW HAMPSHIRE 



WRI ABU Concord 



NEW JERSEY 

W2FLY Camden 

WR2ADD CherryviHe 

WR2AQB Oenville 

WR2ABM Fords 

W2SJT Harmony 

WR2ADO Montcfair 

WR2ADV ParamusPL 



WR2ADO 
WR2ADJ 
WR2AEE 
WR2ADE 
WR2ACY 
WR2 



Ridge wood 
Say rev i lie 
Snme rville 
Trenton 
Whippany 
Wo odd iff 



169-106 
640-100 

6.19-5.79 

6.34-6.94 

6.376.97 

5.66*7.21 

52.88-52.525 

7.93-7.33 

52.2552.80 

6.07-6.67 

444.50449.50 

6.286. B8 



MONTANA 




WR7AOY 


Billings 


6.34-6.94 


WR7ADN 


Bozeman 


6.28-6,88 


WR7ABY 


Butti-Anaconda 


6.346.94 


WA70AA 


Great Falls 


6.280-6880 


WA7KZZ 


Helena 


6.16 0.76 


WA7KZM 


Missoula 


6.16 6.76 


WR7AO0 


Sweet grass 


6.34-6.94 



6.346.94 

6.046.64 



ii e-184 

6.346.94 
6,347.48 

6.947.48 



6.346.94 

444.55449.55 

53.68-53.08 



6.22 6.82 
7.975-7.375 

6.38*6.395 

44740449.40 

6.22-6.82 

6.22-6.82 

7.94*1345 

6.19-6.79 

448.10443.10 

448.55443.55 

6.16 6.76 

186*1255 

6,07-6.67 

7.63103 

6.35*6955 

6.19-6 79 



MORE NEXT MONTH 
Send any and all corrections, updates 
or new listings to 73 Magazine, 
Peterborough NH 03458. 



10 



73 MAGAZINE 






REPEATER OWNERS 



Don't Take Chances. SENTRY offers custom made crystals made exactly 
to your specifications. When it comes to crystals for your repeater, BUY THE 
BEST -SENTRY. 



I'lVi'iVUVt 



:■■ 



'>.'_■".«>_" 






.Oa ■•?.' 



ft^S. 



.-.-.■■. 






& 



REPEATER USERS 



If you want reliable access to the repeaters in your area, you want and 
need SENTRY CRYSTALS. SENTRY CRYSTALS are custom made for your 
rig. We don't stock a large quantity of crystals for a certain frequency and 
hope you can tweak them to frequency in your rig. We do offer FAST service 
on crystals made especially for you and your rig. If you want reliable, 
on-frequency operation, INSIST ON SENTRY. 




SENTRY MANUFACTURING COMPANY 

Crystal Park, Chickasha, Oklahoma 73018 



PHONE: (405) 224-6780 

TWX-9 10^830-6425 



OCTOBER 1974 



11 



and sometimes he runs his own 
beacon." Erik lists a number of 
stations worked including WB4PXW, 
W2RE8, WA4EFB, W3BWU, K2ZYX, 
W5WAX, K8MMM, K7PXI, XE1GE 
and K0HHB. 

SMIRK had 466 members in 44 
states as of August 1st Membership 
applications should be sent to Ray 
Clark, K5ZMS/5, 7158 Stone Fence 
Drive, San Antonio 78227. Ray says 
he heard TG9KJ on CW the 9th of 
July, XE1GE and XE1FE also CW on 
the 10th and passes along that Joe 
WA5HNK heard LU3EX on CW the 
1 2th, 'Bert, K5HVC told me he heard 
an Anchorage, Alaska butane gas com- 
pany testing their transmitter at 0230 
this morning (July 26th) on 49.955 



for about 35 minutes/' Ray says 
JA1RJU has sent in his membership 
application, Kazuo is editor of Japans 
"CQ Ham Radio" magazine. 

The (Indiana) 6*6 Club is now at 
126 members and still growing 
rapidly. The first gold star for working 
25 members went to WA9MEM. 
Congrats Mike! 

Did you work WON R 1 70/7 on the 
Wyoming/South Dakota line during 
the June contest? The many who did 
appreciate the effort expended in 
getting the camper properly posi- 
tioned. 

The East Coast VHF SSB Net meets 
at 1500 CUT Sunday on 50.175. Ray 
K2EGH is net control for this fine 
group. 



WA1EXN worked TI2NA on July 
2nd, and enjoyed every second of it 

On several occasions I have been 
requested to mention the desire of 
one group or another to make 
schedules for a particular contest or 
activity. I am more than wilting to do 
this if the information is received 
early enough. The most recent request 
is typical of the problem. The request 
was mailed July 25th, the deadline of 
the next column was August 10th. 
This column was for the October 
issue, which is distributed in late 
September. Unfortunately the contest 
in question will have been completed 
two weeks before publication* Please 
allow enough lead time on requests of 
this sort. WA0ABI 




Dave Ingram K4TWJ 

Rte, 1 /, Box 499, Eastwood 1/77. SON 

Birmingham A L 352 1 

The enjoyment in seeing pictures of 
the fellow operators you contact, 
their family, rigs, even pet projects 
slowly unfolding down an SSTV mon- 
itor screen is rather difficult to des- 
cribe. SSTV permits QSOs to be more 
like an actual visit than just a quick 
chat What do you do when you visit 
one of the local gang. . .look over the 
rig, start discussing new ideas and 
draw up some sketches or, if it's 
electronic, maybe block diagrams or 
schematics for mutual discussion? 
Sure. . Jt's just typical "ham" nature. 
What better reason could we have for 
SSTV! Slow scanners naturally 
become a rather close knit group 
because they have an additional means 
to really learn about each other. Dur- 
ing picture transmissions a Slow 
Scanner might reveal his interest in, 
say, vintage automobile restoration, 
only to find one or two of his viewers 
also automobile enthusiasts. Follow- 
ing QSOs would naturally lead to the 
"look what we ran across when.. ." 
bit followed by pictures and ideas 
many magazines would relish. 

Slow Scan TV reminds one tremen- 
dously of early ham radio days when 
operators built and tried practically 
anything reasonable. Further, these 
early ham operators seemed to all 
know each other personally because 
of the common "wireless" link and 
the time they took to actually com- 
municate with each other. Why should 
we, in this modern age, contact some- 
one thousands of miles away and then 
stare inadvertently at the receiver dial 
or speaker trying to visualize them? 
Just as commercial TV filled the void 
of early radio programs, SSTV can fill 
the void of audio only QSOs. Today's 



SSTV operators are modern day 
pioneers who want to share their 
enthusiasm. Slow Scan TV is a wide 
open field of tremendous fun, where 
major advancements are still being 
made on an individual basts. (Manu- 
facturers are having difficulty keeping 
up with us!) Why not join in the 
excitement. It is, indeed, amazing to 
see pictures of a beautiful sunset 
across Africa's plains from ZS3B, a 
live volcano from Z2AAV or a 
Tasmanian Devil from VK5BS one 
night and Israeli IDs, some beautiful 
girls or even schematics of new cir- 
cuits the next night 

No longer must amateurs be con- 
cerned with only their voice; now 
they must watch their looks! Your 
physique is on the air, old boy! "Is 
that a beard you're growing, or just 
poor lighting?" "Hey — didn't you 
forget a neat shirt?" "Look at my new 
linear!" That's just part of the excit- 
ing new world of Slow Scan TV. 

If you're not into SSTV now 
t . . may be you're looking over this 
column out of curiosity) why not 
make it a point to visit one of the 
SSTVers in your area and judge for 
yourself? If you are an active SSTVer, 
why not offer to give a SSTV demon- 
stration for your local club. Either 
way, I'm sure the results will be 
gratifying. Should you be interested in 
homebrewing a simple SSTV viewing 
adapter with a minimum of cash 
outlay, consider the oscilliscope view- 
ing adapter described in June, 1970 
QST. It makes an ideal "Beginning 
SSTV" project 

Hams are not the only ones finding 
SSTV a useful communications tool. 
Schools and hospitals are now con- 
sidering it as a mass instructional 
means. One of the more popular 
methods is to lease an FM stereo 
station's subcarrier for transmitting 
the SSTV, then to use a subcarrier 
receiver "in front" of a SSTV monitor 
(or scan converter) for reception. As I 
mentioned a few months back, com- 
mercial scan converters are still using 



scan converter tubes, and prices are 
quite high. Commercial MOS Shift 
Register type scan converters are 

presently not economically feasible. 
Police departments are also finding 
SSTV very useful. Using SSTV, posi- 
tive identification of a suspect can be 
made from a patrol car before arrest 
thus preventing any possible counter 
suit due to mistaken identity. Gee, 
before long police cars may be a 
rolling SSTV studio! I suspect a snap 
on camera adapter would be advan- 
tageous for daytime use, or "mug* 
shots" dispatched to units. However, 
SSTV is still less expensive than faxsi- 
mile units some cities considered 
using. 

This month's SSTV picture is com- 
pliments of George WB9LVI, and 
points up a slogan that's growing in 
popularity. The picture was scan con- 
verted from Slow to Fast using his 
digital converter, which does quite 3 
good job. If it seems like I'm pushing 
this month to get others interested in 
SSTV, you're right We SSTVers have 
a grand thing going. Remember, new- 
comers are vital to the growth of Stow 
Scan, and the more there are the more 
we all have to share. 

The W0LMD Fast to Slow Scan 
converter described in last month's 73 
is destined to be a SSTV classic. This 
is the "black box" unit that connects 
to any regular Fast Scan camera (like 
those inexpensive closed circuit jobs) 
and outputs with SSTV, No modifica- 
tion to the camera is required. . ,just 
plug it in and go. No doubt this unit 
will prove a real advantage to 
SSTVers. Possibly your magazine 
store still has a copy, in case you 
missed it. If not, you can order it 
directly from 73 Magazine, Peter- 
borough NH 03458, for SI. 

Here's a thought you might keep in 
mind for future reference on the 
complimentary transistors used in 
electromagnetic deflection circuits. In 
a bind, try 2N697s for the NPN and 
SK3020s for the PNP. If current 
requirements are exceptionally high 



12 



73 MAGAZINE 



you can always parallel two of either 
type. As the scanning frequencies are 

low, we can pul! quite a few short cuts 
like this. 

Recently, Harry Mills K4HU, 
furnished us some very interesting 
information on the early scanning disc 
TV system I mentioned in last 
month's column. Harry, who during 
the late 20's was an engineer with 
RCA, told of receiving these pictures 
rather well. They were transmitted by 
WGY in Schenectady NY on the 
broadcast band, WGY would conclude 



radio programming at midnight and 
then transmit TV from about 12:30 — 
1:00AM, An early "crater" tube, man- 
ufactured by Daven Co*, coupled with 
a metal scanning disc approximately 
41cm (16") in diameter gave 5.08cm 
(2") pictures. Fantastic! The only 
complaints I've heard is by the time 
you had adjusted the disc speed to 
sync, there was little lime left to view 
pictures. I'm sure you can compare 
this to those first SSTV QSOs, which 
seemed so short, and you kept staring 
at the monitor afterwards, watching 



those pictures slowly decay. Inciden- 
tally, f am presently completing con- 
struction of a scanning disc trans- 
mitter, monitor and receiver, and 
applying for special permission to 
transmit these pictures on 80 and 
20m (1975 is the 50th Centennial of 
TV.) If all succeeds, I will have a full 
story, along with a very simple and 
inexpensive converter, plus a cutout 
for the actual disc to use here in 73, If 
it sounds like fun, drop me a card 
now. I need all the support possible 
for assu red success* K4TWJ 




By; Gus IVL Browning, W4BPD 
Drawer "DX" 
Cordova, SC 29039 

Looks like all the big conventions 
for this year are about through with. I 
did get to go to two of them, one in 
Jacksonville, Florida and the other 
over in Atlanta, Georgia. Both were 
well attended and looked very 
successful. I noticed that Transistors, 
ICs, printed circuit boards and all the 
new small size communication tools 
are getting more plentiful all the time. 
The big heavy stuff is not there like it 
used to be. If you are not "in there" 
starting to get your feet wet with 
these new "tools" of ham radio, you 
had better soon start or you will be 
left by the wayside. As for myself, I 
had been fooling around mostly with 
IC dividers, and the various gates, etc. 
Finally, last week, I bought three of 
these little Phase Lock Loops to foof 
with. I only wish I had more time to 
devote to this side of ham radio. 

I hope all of you worked the boys 
on Kingmans Reef, due to a number 
of difficulties they did not get to stay 
there as long as they had planned, and 
they didn't get on the low-bands, I 
suppose this still leaves this Brand 
New DXCC on the "most wanted rare 
country" list for many fellows and it 
would not surprise me if someone 
goes back there again within the next 
year or so. We all hope they can stay 
long enough to remove the reef from 
the "rare" list for a while. But, keep 
in mind that even a country with one 
fairly active ham stays on the rare list 
for a lot more people than one with a 
24 hour, round the clock operation 
that lasts for three or four days by a 
DXpedition. DXpeditions usually send 
out QSL cards pronto for all their 
contacts or at least to the fellows who 
send them a card. This is not true 
100% of the time with fellows who 
have a whole country to themselves. 

I have been reading about the up- 



coming frequency allocation meeting 
and the possibility we could end up 
with a couple new bands, perhaps get 
a few more kilocycles on some of the 
bands we now have and that we may 
lose a little on a UHF band. Except 
for that last item, the whole thing 
sounds pretty good and I hope we will 
have a lot more "gains" than "losses" 
when the meeting is through. That 
will be the time for that "log 
periodic" antenna that covers a whole 
flock of frequencies. I don't know of 
any antenna that can do that, unless 
it's a sort of multiple, long wire deal, 
one with many lobes in many 
different directions. Maybe some 
smart fellow will come up with a 
brand new antenna type. Anyhow, 
let's QRX and see what the outcome 
of the frequency allocation 
conference is and let's all hope for the 
best. 

They say the sunspots are still 
getting lower and lower in number, 
and no one seems to really know 
when they will hit the bottom. The 
fellows are still working plenty of 
good DX; I guess they must work it 
fast when openings are short, or else 
there are more openings than the 
sunspots would indicate there should 
be. 

Something that would interest 
every DXer would be a serious study 
of some of the very excellent DX 
QTHs of some of the DXers who so 
consistantly put out signals that are so 
much louder than other stations in the 
same general area, I have in mind such 
stations as W3CRA, W9ADN, 
exW4FU (the old original QTHJ, and a 
few others. These fellows put a con^ 
sistantly louder signal into the far 
corners of the world than the average 
first class station. I so well remember 
that S7 signal from W3CRA over in 
the Indian Ocean and up in the AC 
spots when no other USA station was 
even being heard. I know most of 
them personally, they don't run any 
"big stuff" at all nor do any of them 
have up any super antennas, Some- 
thing in the "lay of the land" or 
something under the ground does the 
trick. It would be very interesting to 
really know what causes those loud 



signals when the band is very poor for 
other DXers, It definitely is not high 
power, IT IS THE QTH and nothing 
else that does the trick- 

I have had here as a visitor Jake 
Ritzen CT2AZ, W0JHY for the past 
couple of months, Jake came in here 
like a ball of fire and he is still a ball 
of fire! He has taken upon himself 
filing things where they belong, 
answering all inquiries the day they 
are received, filling the Coke machine, 
sweeping the floors, running up town, 
delivering and picking up, cleaning out 
the car, cleaning up the yard, keeping 
the grandchildren from the print shop 
and going out to a farm to pick 
various vegetables from the farmer (at 
very good prices). He just keeps on 
going all the time and so far has not 
slowed down at all. By the time this is 
in print he probably will be working 
up at a calculator manufacturing plant 
in Lexington, South Carolina, I am 
sure Peggy and I will miss him and all 
the FB work he has been doing 
around this establishment. Jake is one 
of these fellows who can't set still and 
twiddle his thumbs! 

There is talk about fellows going to 
Aden, Iraq, Ctipperton and other rare 
spots. I would suggest that if any of 
you need these three, that you keep 
your ears glued to the bands or 
subscribe to the 73 Magazine, 
"HotMne" or my DXers Magazine, 
AP2KS is trying for Burma, too. Let's 
all hope every one of them is 
successful in their plans and wishes. 
Seems like the bands more or less 
open automatically when a real active 
DXpedition is in the rare country. I 
guess there are a lot more openings 
than the sunspot count would indi- 
cate. Of course, the serious DXer will 
stick in there with a S~1 or S-2 signal 
and work the fellows. 

Some of the DX that has been 
worked in the past few months: 
A51PN (Bhutan), FOSDY (French 
Polynesia, FR7ZL/T-Tromelin (hope 
they get his card), FK8BB-New 
Caledonia, JT1 AT Mongolia, KP6KR, 
Kingman Reef, KP6AL-Palmyra 
Island, KP6PA-same spot, TL8ET- 
Central African Republic, TN8BK- 
Congo Republic, 3D2FC-Fiji Islands, 



OCTOBER 1974 



13 



9 X5PT Rwanda, A 35 FX -Tonga 
Island, BV2A~Formosa, CN8BO 

Morocco, C-21DX-Nauru Island, 
HKBBKX-San Andres, S-2-Bengladesh 
(SM2DWH/S2), VK9N I -Norfolk 
Island, K9KGA/6W8-Senegal Rep„ 
HR6SWA-Swan Island, KA6WT- 
Ryukyu Islands, TA2BK-Turkey, 
TA2SC-Turkey, VU2GDG-lndia, 
VE6JL/SU Egypt, 9N1CK-Nepal r 
9M2GV-West Malaysia and quite a few 
other DX stations. All these are so 
called "poor ' conditions. Should be 
interesting to see what DX will be 
worked when conditions are again 
"good!" 

DXQSLInfo: 
HR6SWA QSLs to H.W,S„ Swan 
Island, P.O. Box 120, Grand Cayman, 
B.W.I. 

KA6WT (his home call is W4TAL) 
QSLs after September to his home call 

om 

VU2GDG via Box 1480, Coimbatore, 

India, 

ZF1ALtoWA4SVH. 

9M2GV viaK6LAD 

VK9YUVK6SW {I am not 100% sure 

of this, but I think it's oJO 

A35FXviaZL2AFZ 

VE6JL/SU-Via the VE6 bureau. 

A51PN viaWUFL 

F08DY via Box 85, Papeete, French 

Polynesia 

FKBBBvia DJ9ZB. 

JT1AT via P.O. Box 639, Ulan Bator, 

Mongolia 

KP6KR via W6WX or NCDXF P.O. 

Box 717, Oakland CA 94604 

3D2FC-Via Box 1250, Suva, Fiji 

Islands. 

DX DUE TO COME UP (at time of 

this writing) 

VP8 (LU?) A group of hams from 
the Radio Club of Argentine is 
planning a DXpeditron to SOUTH 
SANDWICH Islands. Plus a group 
from the West Coast (not sure of 
which West Coast DX Club they refer 
to), probably NCDXF group. Their 
plans are to be on South Sandwich 
either in November 1974 or January 
1975. This will be a 4 day operation 
with all bands and modes being used; 
even will try to work the fellows in 
the Novice portions of the bands. 
They say that no certain group of 
fellows will be "'favored/' meaning I 
suppose that they will get stations all 
over the bands. 14275 up, etc. You 
had better make your plans to get this 
one, fellows, because it will cost 
plenty of money and probably wilt 
not be repeated again very soon. 
Getting to countries below the Ice 
Pack is big trouble, big boats and big 
money! I so well remember my trip to 
Bouvet Island. 

SV1GA/A Mt. Athos - should have 
been on and finished by the date you 
read this. The trip is planned by those 
old faithfuls OH2BH, OH2MM and 



3V1GA. I would suppose the cards 
should go to Martin-OH2BH. 

C21DX by JA10CA, HBO Late 
July, early August by DA1QC, 
HC2YL is Darlene fellows, HC2TV 
plans for some low frequency opera- 
tion in October, will be trying for 
5BDXCC while there and even some 
160 meter operation. 

Pacific DX net meets regularly at 
0600z on 14265. If you are not a net 
member please wait until they call for 
non-members to check in. They 
generally have a few good ones check- 
ing in, and you might be lucky and get 
the one you need. 

VK9YU, Cocoa Keeling plans to be 
active up until about October 1st 
(more or less). 

During the QRP tests from the 
Pacific with W6WX using only 1 to 2 
watts a good, usable signal was being 
heard in W4-land on 14100 kc 0400 
to 0600 GMT. This was W6WX/WIM in 
July while on the Kingman Reef trip 
with the other fellows. 

VK2BKE/LH is now active and 
plans to be there for ONE YEAR. Was 
worked on 14265 kHz around Q60Oz. 

BV2A has been working them on 
CW and by now should be on SSB, 
This is Frank, W9ZNY. When you 
hear HR6SWA you are hearing exKS4 
land (Swan Island), They now only 
count for HR land now {except WTW 
still counts them as Swan Island). It 
has been suggested to me, by quite a 
number of DXers, that a rare DX 
station who is stuck with a transceive 
situation should go the "MC" route. It 
seems that when strictly transceive is 
used the situation slowly gets out of 
hand, then no one can hear the DX 
station because someone is ALWAYS 
CALLING. I listened to quite a mess 
when VE6JL/SU was on transceive 
and the fellows started the "chain- 
calling/" when one stopped another 
started and this went on for quite a 
while. When they all finally came up 
for "air" the station in Egypt had just 
QUIT (and I don't blame him either!}. 
It's a shame about things like this. 
Even the district by district of work- 
ing the boys did not work out because 
too many fellows called out of order. 
W9DH tells me that the control was 
all shot by the time he got to W9, I 
guess the MC route is better under 
these conditions. 

LETTER TO EDITOR R.E. DXCC, et 
al 

Dear Gus 

There seems to be a lot of contro- 
versy lately on what constitutes a 
"country/' so here's my suggestion on 
how to please (almost) everyone. 
Although I'm not particularly a 
"certificate chaser" let's also realize 
that the more awards available, the 
more DX activity we stir up (WAS for 



example). Therefore, why not have an 
award for ail DXers, regardless of their 
difinition of "country," 

AWARD NUMBER ONE; for the 
purist — this award would be for 
working "political countries/' KH6 
would be USA, Latvia would be 
USSR, Ceylon would be Ceylon, Mt. 
Athos would be Greece, etc. The U.N. 
or LT. UIARU would be naturals for 
sponsors. 

AWARD NUMBER TWO: For the 
Political Scientist — include Colonies 
and Dependencies as separate 
countries, but exclude the islands 
reefs, or anything which can't be 
classified as a political or a colony 
thereof* This admittedly is a weak 
definition (ambiguous) but someone 
should be able to put it on paper 
properly, 

AWARD NUMBER THREE: For 
the guy who resists change — Present 
DXCC country list 

AWARD NUMBER FOUR: For the 
DX Hound/Geographer. Include all 
countries, colonies, islands, reefs, 
dissenting autoomies, etc. All 
Canadian, USSR, Papanese, etc., 
provinces, the fifty states, and any- 
thing which can be found to have any 
basis for separate listing should be 
included even separate the 5 
Hawaiian islands. 

This way, you could pick the award 
that matched your definition of 
"country" and the award chasers 
would have 3 new ones to work for. 
And it certainly would not decrease 
DX activity or demand for W/K types. 

„ , ,WA0TAS 

What do you think of this, fellows? 
Looks like Award number four fits 
our soon to come out Super WTW. 
None exactly fits our present WTW 
though - since we call our 
'countries' all that's listed on DXCC, 
REF, DARC, WAP, etc., lists. In fact I 
still say, there must be a better word 
to use than "country" in our DX 
language. How about some of you 
fellows who know of a better word 
making a few suggestions to me? 

When someone asks you how many 
countries you have worked and you 
say 300, they usually ask, "Are there 
300 countries in the world?" About 
that time you try to change the 
subject to something else because you 
just cannot explain to anyone that 
Geyser Reef, Blenheim Reef or 
Kingman Reef and other similar places 
are "countries." Seems to me if such 
places are being called countries that 
ALL ISLANDS should be called the 
same thing. There I have said my 2i 
worth again, not that anyone is going 
to pay me the least attention! 

The hook is clean here for this 
month fellows. How about some of 
you out there sending me a lot of 



14 



73 MAGAZINE 




you 




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good DX info for this page? I am sure 
a little publicity would not hurt any- 
one. We will of course mention your 
call as the source of the DX info you 
send to me, 73 till next month. 



73 es DX, 



de, 



"JUm. 



BPD 



GOING 
FIRST CLASS! 



Using the EBC-144 Jr. 2m 
Transceiver 



Synthesis, with no limitations, is 
the name of the game with the new 
Emergency Beacon transceiver. For 
the first time we were able to dial up 
even the most oddball of repeaters. 

The ads for the Emergency Beacon 
"Dream Machine'' transceiver — a rig 
which could obviously do everything, 
including scanning, total synthesis, 
tone burst, continuous tone, Touch- 
tone, 600 kHz splits, 990 kHz splits, 
one meg splits, simplex — and you 
name it — the ads for this rig got a lot 
of fellows all excited, nervously 
putting away money now and then in 
case they talked themselves into 
getting one. 

Unfortunately, as with most pieces 
of really sophisticated equipment, the 
delivery on some of the special parts 
required to put the rig into produc 
tion stretched on maddeningly and 
the boys at Emergency Beacon 
decided to proceed with their secon- 
dary project, a junior model of the 
Dream. This is the EBC-144 Jr and it 
has all of the basic functions of the 
big rig such as synthesis down to 5 
kHz steps, a priority channel scanning 
system, 600 kHz high or low split 
automatically for repeater operation, 
provision for connecting a scanner, 
and things like that. 

The fellows at EBC were not only 
having problems getting the zillions of 
parts needed for the big unit, but they 
also found that while bread and milk 
had inched up only 25 to 50%, the 
prices on parts had in many cases 
doubled and tripled! This brought the 
price of the big rig from about Si 000 
to $1500, with many signs that even 
this stiff price might have to be 
increased substantially. The customers 
who placed their orders at the early 
price had indeed gotten in on a very 
good thing. 

The Junior has been priced at $599 
for starters. We'll be greatly surprised 
if this doesn't go up before long. And 



considering what the rig does, even at 
$600 this has got to be one of the best 
bargains in ham gear on the market 
today. 

One of the first moves we made 
with the Junior was to mount it in the 
73-mobile and head for the top of the 
local mountain to see how it would do 
up there in the high density rf that 
prevails. We checked it Out on every 
repeater we could reach — and we can 
reach a bunch from up there. All we 
had to do was set up the "A" channel 
on the repeater output and switch to 
'Auto" on the mode switch and we 
were right in there. 

While not too many rigs can 
weather the rf storm on top of the 
mountain without intermod and other 
garbage, the Junior was absolutely 
quiet. Even the several local 
commercial repeaters didn't break 
through! And they put out a lot of 
microvolts. Next we started checking 
out the splinter repeaters to see how 
the Junior could handle the 15 kHz 
spacing — particularly when the 
repeater was right in the next channel 
to a strong and oft used repeater. For 
instance we checked into WR1 ACL in 
Salem NH which is set up on 147 .1 65, 
right between WR1ABB in Framing- 
ham (Mass) on 147:15 and WR1ADF 
in Bridgewater (Mass) on 147.18, both 
of which are pretty active. Oh, we 
could hear some crosstalk, but it 
wasn't enough to hurt anything. It 
proved that it is possible to build a 
receiver which can handle the 15 kHz 
splits. Both ADF and ABB pinned the 
meter, which ACL was only about 
half way up atS-6. 

Next we dialed up WR1ADC in 
Somerset (Mass), a 990 kHz repeater 
with input on 146.43 and output on 
147.42. No strain with the Junior — 
just set the mode on "Split" and put 
the receive channel on "A" and the 
transmit channel on "B" dials, and 
kerchunk, there was ADC, loud and 
clear. 



Aha, what about that private closed 
repeater in Manchester NH, the one 
with the secret input channel? We 
knew their input had been around 
145.88 or so in the past and the 
output on 147.33 so we set up the rig 
to listen on 147.33 and, sure enough ( 
there was the repeater with someone 
talking away. We quickly dialed up 

145.88 and moved up and down, 
centering on 145,89, listening to the 
repeater input. Next we set up "A" on 

145.89 and "B" on 147.33 in the 
Split mode and broke in with a short 
"Hello." It worked! "Who was that 
who broke in and said hello?' We gave 
our call and they promptly turned off 
the repeater. They do that to anyone 
who calls in who is not a member of 
their small closed group. There may 
be more unfriendly repeaters in the 
country, but word has not reached us 
about them. This is most distressing to 
the rest of the New Hampshire ama- 
teurs, who are rather proud of the 
warm and friendly reception they give 
visitors on the other New Hampshire 
machines — and there are a bunch of 
them. 

Just to bolster our confidence in 
2m FM and be reassured that the 
reception on WA1KFV was highly 
unusual, we checked into WR1ABQ 
on 25-85 in Derry NH, WR1ABU in 
Concord NH, WR1ACQ in Deerfield 
NH, WR1ACN in Londonderry NH, 
WR1 ABF in Salem NH, and WR1ADX 
in Wolfeboro NH. All were outstand- 
ingly nice. 

The reports on the rig were most 
complimentary — not only was it right 
on channel, but the audio was superb. 

True to the "Never Say Die" motto 
which is more than a catchword at 73, 
we set up the rig to work on channel 
"A" and listen in with priority on 
channel "B" on 147,33 so we could 
hear KFV when they turned it back 
on again. After a while someone did 
tone it on and we knew it imme- 
diately for the Junior works fine on 




16 



73 MAGAZINE 



channel A, but every few seconds it 
flips briefly to B to see what is doing 
there and then back to A again, That 
little function keeps you from missing 
anything. Fortunately cooler heads 
prevailed and nothing was done to 
further invade the privacy of the KFV 
group, despite some of the inffamma- 
tory remarks that were being passed. 

In most cases where a repeater 
suffers jamming and heavy kerch unk- 
ing, you'll find that there are some 
good reasons why this repeater has 
been singled out for harrassment. The 
KFV group is certainly asking for it, 
but since few ops have synthesizers as 
yet — particularly synthesizers which 
will cover the entire band and go 
down below 146*0, they've been rela- 
tively free of troubles. The Junior 
covers from 143.5 to 148.5, thus 
making it simple to get into all of 
these weirdo repeaters as well as 
MARS and even CAP repeaters which 
are just outside of the 2m band. 

In the Automatic mode the rig 
transmits 600 kHz fower than the 
received channel within the 146 MHz 
segment and transmits 600 kHz higher 
in the 147 MHz segment, per the 
standard used just about everywhere 
in the country now. Some of the 
repeaters on 147,00 MHz have their 
input on 146.40, so you have to turn 
the mode switch to reverse for this. 
There are a few repeaters In the 147 
segment which have input low and 



this will solve that problem too. Band 
openings and inversions drive these 
non-standard repeaters batty as they 
lock up on other repeaters sharing 
their channels, but with reversed 
input/outputs. 

The Junior has a big plus in the 
back which mates with the EBC 
scanner and turns your receiver into a 
six channel scanning receiver. More 
about that extra option when we have 
a chance to check it out at length. 

The transmitter is rated at 20 watts 
output, but the Bird Wattmeter indi- 
cated close to 25 watts on our unit. 
You don't really need an amplifier 
much when you're starting out with 
that amount of power. 

The Junior has a built in speaker, 
like most 2m rigs (but not all), plus a 
jack in the back for an external 
speaker (we prefer to use the external 
speaker in the car which is mounted 
where it can easily be heard). 

While there is not a lot of activity 
in New England below 146 MHz, with 
the exception of Oscar and a couple 
of repeaters which still have inputs 
below 146 (WA1KFV and WR1ACY 
in Glastonbury CT 145.47-147.09), it 
is nice to be able to tune down and 
actually hear what is going on in the 
rest of the band. The Auto function 
on the mode switch cuts out below 
146 and the rig is simplex in that part 
of the band automatically. You'll find 
that the AM boys, what few there are 



left of them, will generally be able to 
copy your FM signals if you feel like 
calling them If the FCC ever does 
open up more of the 2m band to 
repeaters, as many ops are beginning 
to think they should, the Junior will 
be able to cover the new band for you 
right off. 

The receiver sensitivity was every- 
thing we could ask — the size perfect 
— the flexibility fantastic. Two meter 
rigs have certainly come a long, long 
way in the last couple years! When 
you consider the savings on crystals, 
even the cost of the synthesized rigs is 
not out of line. The Standard 1400 rig 
that we used for a couple of years 
required 44 crystals — at S4 each that 
came to $176 in crystals afone! Even 
if you've been managing to get along 
with a 12-channel rig, that's $96 
investment in crystals. 

One has to face up to a simple 
philosophical question — are you 
going to be satisfied to stick with one 
or two repeaters or are you the type 
of person who wants to be able to use 
all repeaters — who wants to have a rig 
that can be taken anywhere and put 
you in touch with what is happening? 
A lot of 2m ops get on one repeater 
and never go anywhere else. Presum- 
ably they are happy, so there is a 
chance that you can get along with 
this limitation and don't need a 
synthesized rig. We feel you'll miss a 
lot this way. 



A MS AT 




NEWS 



Michael Frye WB8LBP 
640 Deauvilie Dr. 
Dayton OH 45429 



AMSAT-OSCAR 7 is scheduled to 
be launched from Vandenburg Air 
Force Base in California on October 
10, 1974, sometime between 
1600-1700 GMT. W6AB will broad- 
cast the countdown on twenty meters, 
AMSAT members will be on the air 
most of the day, two frequencies to 
monitor will be 14,280 kHz, and 3850 
kHz. 

i 




— 


7 

1 


4 V_jA 

i ■( nil 

_ 

H 

-/i M 

i 



Jan King W3GEY, A-O-B Project Manager 
installing A-O-B in Thermal Vacuum for 
testing. 



AMATEUR SATELLITE 
MATCHING FUNDS 

William Eitel WA7LRU/W6UF 
and Herbert Hoover, III W6APW T 
have generously offered to 
match, dollar-for-dollar up to a 
total of 525,000, donations to 
the ARRL Foundation ear- 
marked for use in the amateur 
satellite program. 

Funds are urgently needed to 
support the construction of 
AMSATOSCAR 8, which is 
estimated will cost on the order 
of $100,000. 

We urge you to support the 
amateur satellite program with a 
financial contribution, Contribu- 
tions to the ARRL Foundation 
are tax deductible under Section 
170 of the Internal Revenue 
Code* 

Thank you for your support! 




Looking for a SUBAUDIBLE 
TONE GENERATOR for your small 
hand held or portable FM radio? 
'THE CUBE" is only 1,27cm x 
1,52cm x 1.78cm (.5 ' x .6" x .7") in 
physical size, but it has a whopping 
sine wave signal out Designed to be 
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guarded systems, it works on 9- 16V 
and has no moving parts. 1 1 can be set 
on any frequency between 98 and 
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CUBE is available from RGS 
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For an extra S5.00, it can be set on 
frequency by the factory. Contact: 
RGS Electronics, 3650 Charies Street, 
Suite K, Santa Clara CA 95050. 

News cont'd on page 1 31 



OCTOBER 1974 



17 



THE 



ultimate 




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• Frequency stability of 0.0005% 

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• One million channels (1000 Rec. x 1000 
Trans.) 



hear 



• Operates on FM, AM or Modulated CW 

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• Frequency range of 143,5 to 148.5 MHz in 5 
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• Sensitivity - ,35/lV for 1 2 dB sinad, 30(IV for 
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• 20 watts output 

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• Independent selectable priority channel 






Priority channel is functional but with the 
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can be "locked out" of scan sequence. Those 
bright yellow LED digital readouts make night 
mobile operations a dream. 

• Scans any 6 channels 

• Indicates offsets 

• No xtals to buy 

• Locks on xmitting channel 

• Easily added to EBC 144 Jr. 

• Room for options, i.e. tone burst, touch-tone 
pad, PL encoding 

• Easy reprogramming of channels 

• Individual channel lockout 



$199.00 







Emergency Beacon Corp. 
15-A1 River Street 
NewRochelle, N. Y. 10801 

Please send me: 

DEBC-144 $1495.00 (S1 50.00 dep) OEBC-145SA 

DEBC-144Jn $ 599,00 (S 60.00 dep) OEBC-7000 

10% deposit will insure early delivery and guarantee price. 

Q Payment Enclosed * ' BankAmericard No. 

nSend further info. D Master Charge No, 

(Include four digit No. above name.) 

Expires 

Name 

St. Address 

City _State 




tnaatef ctiArgm 



$199,00(520 
$399.00 (340 



00 dep ) 
00 dep > 



Zip 




-M 



H.T. Orr W6EIF 
249 Juanita Way 
Placentia CA 92670 





«4«>f 




as seen 




The Irate Neighbor with TV I 




■:-:-■■ 






WATTS 



.-.--■.-■-■' 



The California DX'er 






YES , ER- UO ) 
ER- YES - W-j 





-&«3l1$ 



& 
&& 




The A RRL 



The Novice 



20 



73 MAGAZINE 




1 &!* 







Tfte Canadian Ham 





The New Two- Letter Call Holders 




ujfetlf 



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21 



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L 





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± 




I ^b V^ V^ a subsidiary of Tucker Electronics Co. 

SURPLUS TEST EQUIPMENT FOR BARGAIN HUNTERS 
P.O. BOX 1050-A 322 KIRBY ST. GARLAND, TX. 75040 

214-348-8800 



Bill Hoisington K1CLL 
c/o 73 Magazine 
Peterborough NH 03458 



Introduction 



to 



U 



MICROTRANSISTORS 



Just how small can the homebrewer 
make an amateur rig - with reason- 
able-cost parts - that works well enough to 
get, say, 50 miles on 6 meters? 

General Electric makes a line of micro- 
transistors called "Microtabs/* and in this 
line are some nice ones that will oscillate at 
frequencies as high as 1 GHz. And Bill 
Ashby of KMC Semiconductors makes 
some that go to 2 GHz. 

Figure 1 shows a sketch of the approx- 
imate shape and size of these little molecu- 
lar firecrackers. Now don't get the idea 
that just because they're tiny that you 
can't work out with them. Lots of things 
come to mind, such as 2 meter FM units 
suitable for repeater operation, and a host 
of other such devices. 

As usual, with a reduction in size of an 
order of magnitude in one component, you 
have trouble getting the other parts down 
in size proportionately. We will deal with 
some of the components that are available 
today for the amateur homebrewer for 
making pocket-size rigs, and cover some 
circuits and modules that can be combined 
into such rigs. 



As you will see even when you build a 
Dick Tracy rig that fits on your wrist, 
you'll still have to think about a micro- 
phone, speaker, and an antenna. Also, the 
average amateur does not have a good I OX 
stereo microscope on hand to work with. 
Nor does he have micromanipulators or 
any of the other devices commonly used 
for microminiature packaging applications, 
either. 

Then there is the cost question. For the 
military or certain specialized commercial 
interests, where money is not the prime 
consideration, paper batteries, thin-film cir- 
cuitry, etc., can be ordered to suit. How- 
ever, there are certain things in this line 
that amateurs can do, and with a little 
prodding of suppliers of tiny components 
(reminding them, perhaps, of the large 



i 



.056 in. 



T 




RED DOT 



E 
C 

B 



Fig. L General Electric D26G-I micro transistor 



24 



73 MAGAZINE 



D26G-I 




+12 V 

LI -25 TURNS 2S AW6 TAPPED 4 TURNS FROM 
COLD END, WOUND ON UB in DIAMETER 
FORM, APPROXIMATELY 1/3 in. LG, 

Fig. 2. Microtransistor crystal oscillator for 50 
mHz, The first LI is 9 turns, airwound, 1 in. 
long, 5/8 in. O.D., tapped at 2 turns from the 
cold end. The final LI was 25 turns of No. 28 
tapped 4 turns from the cold end and wound on 
a 1/8 in. form about l A in, long. 

percentage of amateurs in the ranks of 
technicians and engineers) can result in 
them shelling out with some very small 
capacitors, resistors, and inductors. Let's 
see what the amateur can do today with 
microcomponents: 

Crystal-controlled Oscillator 
for 6 Meters 

When you first connect one of the tiny 
little micro transistors as an oscillator, it's 
kind of startling to see the rf meters move 
and bulbs — which are several hundred 
times larger — begin to glow. And it's even 
more of a shock to find that amateurs 
miles away can hear you also! What kind of 
power are we talking about? A good solid 
100 mW input for a starter. The GE job is 
rated at 90 mW dissipation "as is" — and 
don't forget, if you can light a bulb on the 
rf you can maintain a QSO over distances 
up to 50 miles! 

A practical circuit of a 6 meter oscilla- 
tor is shown in Fig. 2, At I2V the 
dissipation maximum of 90 mW is soon 
reached with 7 to 8 mA. But, at 40 to 50% 
efficiency you've got almost half of the dc 
input power going up to the antenna, so 
you can probably use 150 to 180 mW dc 
input once you get everything tuned up 
and have good output. 

Details of component size, mounting 
methods, test layouts, and output checking 



circuits are found in the following para- 
graphs. 

Size Reduction 

This is not easy, if you're trying to 
match down to the size of the device. On 
the micrometer the D26G-2 shows 54 mils 
(thousandths of an inch) thickness and 
about the same for length, which comes to 
less than one cubic sixteenth of an inch in 
volume. You have to use tweezers even to 
think about mounting it. We do have 
resistors to match, almost. The 1/1 0th watt 
Allen-Bradleys are only some six times 
larger, and Sprague Electric in Nashua, 
N.H, makes some even smaller. Perhaps 
some readers know of some that match the 
device in size? 50th watt? 100th watt? 

Capacitors are getting near to size also, 
with Mucons, made by the Republic Elec- 
tronics Corp., Paterson, N.J., about 4 to 5 
times bigger than the device. These are 
cylindrical in form and only 60 mils 
diameter, so they fit nicely in small places. 
You can see that we're still a little ways off 
from complete size matching, but it will do, 
for a starter. 

Next comes LI and this is really a 
project. We'll go through a sample run to 
show you what's involved. There are mi- 
cro-coils in existence, but I can't see 
advising homebrewers to use a lot of coils 
that cost $3 to $4 at this time. Let's see 
what we can wind up as quickies for 
pennies for ourselves out of a few inches of 
small wire and impregnated paper forms. 
You will see 75 mW rf output to let you in 
on an advance secret. If a satisfactory 
tuning core can be obtained to fit into a 
l/8th or I /16th inch form, and which will 



FIBERGLASS OR 
LINEN BASE 
BAKELITE 



COMMON PINS 




FIBERGLASS 
SHEET, 5 OR 
6 MILS THICK 



BASEBOARD 



l- CEMENT ASSEMBLY TO BASEBOARD USING COIL DOPE 

FOR PERMANENT USE 
2- USE HiGh -0 COIL WAJC FOR TEST SET*UP 

Fig. 3* Side view of mounting terminals. Note: 

cement the assembly to the baseboard with coil 
dope for a permanent unit. Use a high-Q coil wax 
for a test setup. 



OCTOBER 1974 



25 



mm 



tune without loss in the 50 to 150 MHz 
range, this will do away with the variable 
capacitor and bring us down to an overall 
thickness for the rig of under 1/1 0th of an 
inch. Right this minute this is just a sort of 
dream, but keep reading. 

Test Mounting 

My immediate thoughts on seeing the 
microtransistor with its 5 mil gold leads for 
the first time concerned the handling and 
mounting. You can get used to this soon 
enough, even though in my case* having 
arrived in this world in 1904, I now use 
fitted glasses with 2X power of magnifica- 
tion. The first thing is the question of 
subminiature "binding posts" (as they used 
to be called), and for new readers a brief 
description follows. Figure 3 shows a side 
view of one method of making these items 
that will only cost you a trip to the 5£, 
10^f, and $20 store. I use the 21 mil 
diameter "Bank Pins/' and drill a 20 mil 
hole in a thin piece of fiberglass or linen- 
base Bakelite. When these pins are driven 
through these holes from the underside and 
then soldered on the top side they don't 
pull out. Figure 4 shows a top view of the 
three pins used with the microtransistors 
and various small capacitors, resistors, and 
inductors also attached, with approximate 
layout for testing. 

You can see the items that need plenty 
of size reduction work , such as the crystal, 
the trimmers, and of course the inductance 
itself. The small one shown here in the 
final circuit however, sacrifices nothing in 
power compared to the "big" airwound 
coil used for tests. It puts out 30 to 40 
mW. 

A lot of the size reduction work men- 
tioned means finding suppliers who can 
furnish subminiature components at a rea- 
sonable cost. This is sometimes a lot harder 
than the benchwork involved. 

Figure 5 shows a handy filter to keep rf 
away from the battery leads where it can 
otherwise cause lots of trouble for you 
when more stages are used, such as ampli- 
fiers and/or multipliers. This trouble by the 
way is very hard to identify as it causes 
feedback paths with odd phase effects 
through the battery leads, You may be 



rf? 



i 



3/S in. 



5K 



JT^h 



.01 




£7h 

TUNE 

5-00 pF 






MATCH 



q@> 



50-350 pF 



3 OUT 



I 



XTAL 



+ JEV 



tt SELECT- JOOa TO 150 a DEPENDING 
ON CURRENT REQUIREMENTS 

LI -9 TURNS p AJRWOUND, 10 T.PL, 5/9 in 00 , 
TAPPED 2 TURNS FROM COLD END, 

Fig. 4. Layout, top view, of circuit in Fig. 2. 

using separate batteries for tests and every- 
thing is going fine, and then when you start 
connecting to a common battery every- 
thing goes suddenly haywire. Use the filter. 

Certain things can be done to reduce 
size after this circuit and operation is 
firmed up. For instance, the main amount 
of capacitance in a large trimmer may be 
obtained by using a fixed capacitor with a 
small trimmer in parallel. The Arco 402 
midget trimmer runs 1.5 to 20 pF and is 
only 9/16ths long by 3/8ths wide. This is 
still "huge" compared to the device, but it 
can be used. 

The same thing can be done for the 
tuning capacitor across LI. The whole 
question of size for tuned circuits is wide 
open so far, as you can easily see. 

Matching Outputs 

Starting out on a try for power (don't 
laugh now, remember that guy who laughs 
last . , . and also the €i mile-per-milliwatt" 
formula) , it seems at first preposterous that 
a tiny speck of material shown in Fig. 1 
could ever generate enough rf to actually 
light a bulb. Indeed, at the first try it only 
showed one volt at the test diode dc 
output (see Fig, 6). 

Incidentally, the matching values shown 
were not arrived at immediately. R4 is very 
important because you can easily draw 
over ten mils with various tuning setups in 
the oscillator itself, as mentioned. When all 
the parameters such as feedback tap, emit- 
ter resistor, LI , CI, the crystal, the transis- 
tor itself, and the proper output match, are 



26 



73 MAGAZINE 



all working together you can then push up 
the output power, with the internal dissipa- 
tion going up to the maximum of 90 mW. 
Assuming an efficiency of 40 to 50%, that 
is, with everything matched and tuned up 
with some half of the dc input power going 
up to the antenna in rf form, you could 
run some 10 mils at 12 volts, or even a 
little more. Note however that if detuning 
or other mismatch should occur you may 
dump all of that input into dissipation, and 
goodbye to your little microtransistor* 

Working with CI and the feedback tap 
on LI, and always with R4, things started 
to pick up, with the output climbing 
toward 5V dc out of the test diode Dl. At 
this point, which indicates some 15 to 20 
mW of rf output, I started checking with a 
No. 48 bulb that glows a dull red on 18 
mW, It didn't light yet, but finally with the 
match shown in Fig, 6 it did, and before 
long, that is, another hour or so, it was up 
to about 40 mW, still keeping the total dc 
input to 120 mW or less. Maybe one could 
immerse that tiny little blob in oil? We 
used to do just that back in the early 
1920's, taking the metal base off the 
"powerful little five watters," which were 
the Radiotron 202 tubes, if I remember 
correctly back to that far-off circa of some 
46 years ago, and put them upside down in 
a gallon can of transformer oil. Then run 
100 watts. I may try this on the little blobs 
if GE or Bill A. sends me a couple dozen 
more devices. That kind of work is usually 
called "test to destruction." 

So finally the output circuits of Fig. 6 
were worked out, using the temporary CI 
and LI and we started reducing these 
components down to size. 

Small Size Tuning Inductors 

There has been a lot of talk about the 
theory of using transistors and making 
them "act like inductors," but so far I 
don't see any on the market. So, while 
watching and waiting we'll get along with 
small coils. You may be surprised at what 
they can do. I was. 

So here we go with spools of small wire 
up to No. 36 in size, and coil forms down 
to 1 /10th of an inch in diameter. 

Coil No. 1 was airwound, ten per inch, 9 



turns, 5 /8th O.D. which was used as a 
standard. No. 2 was 12 turns of No. 20 on 
1 /8th inch paper tubing. It worked fair to 
good, but required nearly 100 pF of tuning 
capacity. No. 3 coil was also on l/8th inch 
O.D. tubing but with 25 turns of No. 28 
dec (double cotton covered), with tap at 4 
turns. It worked as well as the first 
reference coil. This No. 3 coil is huge 
compared to the device, but there is a 
question of just how much time you can 
spend on microcoils. Coil No. 4 was 25 
turns of No. 38, tap at 5 turns, two-thirds 
jumble wound. It oscillated well, but only 
had about one half power out. No, 5 was 
25 turns of No. 34 dec, tapped at 5 turns, 
90% jumble wound, with output tap at 3 
turns. Only fair output. Referring back to 
coil No. 1, it was found that the use of a 
tap instead of a separate link output 
winding gave more output. Coil No, 6 was 
25 turns of No. 26, tapped at 4 turns for 
the emitter and 2 turns for the output. 
Output went up to 5,5V, holding the 
current at 6 mils. Tapping on the output at 
4 turns along with the emitter brought the 
output up to 6V. This looks as though we 
are zeroing in on what is needed. This No. 
6 coil is 5/8th of an inch long and the 0,D. 
is about 3/1 6th of an inch, which may be 
the best compromise for now. 

Checking to see how close to the cop* 
per-clad baseboard such a coil could be 
placed it was found that there is only a 1 
or 2% reduction when the coil was prac- 
tically touching the copper. To be exact, it 
was about 1/32 of an inch away. The tap at 
two turns was almost as good - . . not too 
critical. The feedback tap at 4 turns and 
output tap at two, worked well, CI is 
around 20 pF and thus the small Arco 




RFC 
.001 ,001 



' 00I LX^7 



^% 



RFC -10 TO 20 TURNS SMALL 
GAUGE ENAMELED WIRE 
WOUND OVER 1/(0 WATT 
RESISTOR, IK OR OVER. 

Fig. 5, Dc battery fitter; C = .001, 1/8 in. square. 
RFC = 10 to 20 turns of any smaJi size wire on 
1/lOth watt resistor over IK* 



OCTOBER 1974 



27 



■I 



midget trimmer can be used, but a check 
was made anyway with reducing the num- 
ber of turns on coil No, 6. With 15 turns 
the output was only 1 ,5 V, so that was n.g. 
Coil No, 7 was 20 turns of No. 28, with tap 
at three turns. Only 2.5 V output. 

We are going to describe an rf amplifier 
and frequency multiplier using these little 
specks, but there are two good reasons for 
peaking up the power from the cyrstai 
oscillator. First, if it's a good oscillator it 
will be more stable and operate well on 
reduced battery power and with aging. 
Second, you may want to try it on the air. 
Modulating a crystal oscillator is perfectly 
legal, at around 80%, and if RCA can do it 
so can we. 

There is an interesting forumla which 
comes out at "a mile per milliwatt/' but 
more on that later- 
Different types of output coupling were 
also tried and while a pi-network furnished 
slightly greater output under certain condi- 
tions, link coupling and tapped on coupling 
light bulbs and furnishes good output 
power to 5012 cables as well. With a little 
more care and testing, the best inductance 
which we have found so far involves a 
rather large value of trimmer, but is easy to 
wind and does light a bulb to around 
40mW and produces well over 5V on the 
diode test. This is shown in the final 
circuit, Fig. 6, where the feedback tap is 
seen to be the output tap as well. It works 
fine, is a strong oscillator, and produces 
good drive into the rf amplifier shown 
later. 

Rf Power Amplifier 

■. 

As suggested before, don't laugh; that 
tiny bug is putting out 75 mW, amplifies, 
matches, tunes in fine shape, and has not 
self-oscillated yet. Figure 7 shows the final 
schematic with the layout as in Fig. 8. I 
started out with dc bias on the base but 
soon found that the oscillators 20 to 30 
mW of rf was enough to push the amplifier 
collector current to 20 mA, which is 
certainly more than the rated amount for 
continuous use. An rf choke was installed 
between base and ground, a usual method 
with amplifiers, and the input was set. 

Tapping the collector down on LI 



D26G-I 




TUNE TO 
50 MHi 



+ 12V 

Tl- TAP AT 4 TURNS FRQW COLD END OF LI. 
T"2 - « « g m •■ >■ p»bu 

USE ONLY T2 OUTPUT OR TJ OUTPUT, NOT BOTH. 
LI-9 TURNS 

Fig. 6. Power indicator and output matching. Use 
only one of the outputs at a time, either the pilot 
bulb or the diode power indicator. 

resulted in better tuning and more output, 
so it was checked up and down LI for the 
best output, which occurs when the collec- 
tor tap is near the middle of L 1 . 

There is an impressive dip in current at 
resonance, always a welcome sign in solid 
state amplifiers, and by varying C4 this dip, 
which is much smaller of course when the 
amplifier is loaded, and the maximum rf 
output, could be adjusted very precisely. 

The emitter behaves according to Hoyle 
also with a smooth climb in mA and 
output power as Rl is decreased from 
13312 down to 33. Be careful there, be- 
cause at 3312 you may be getting too much 
current. 

I'll have to get more information from 
GE on the question of maximum dc power 
in and rf out, because they rate this chip at 
90 mW dissipation. With 14 mA input at 
12V, for a dc input of 168 mW, it puts out 
at least 75 of rf, and 75 from 168 leave 93 
raW, which is the present rated limit. These 
devices are not expensive however, so it is 
more a question of the trouble of opening 
the shielding enclosure and soldering in a 
new device. 1 have a drop of wax on the 
outside of the plastic case to see if it gets 
hot enough to melt, but that may not teU 
the proper story. Even if it was a metal 
case, there is a real tiny chip inside that can 
get hot and melt if the internal leads do 
not carry away the heat to the outside. 
This whole rig is supposed to eventually fit 
inside a cigarette-sized package, so perhaps 
we should be content with a good clean 75 
mW. There is also the question of mqdula- 



28 



73 MAGAZINE 



o 



x 



Oi 



i 



0260-1 



FROM 
OSC 




* 






RF 
OUT 



i 



Ri 
IOQjv 



01 ?F?30^4?30pF 



pF JOHNSON 

/77 /77 TYPE W 



/77 



LI = 9T AiRWOUND. iO TRL 

COUXCT0R TAP AT CENTER 
OUTPUT TAP AT 1-3/4 TURNS 

Fig. 7. Micro transistor rf power amplifier. LI = 9 
turns wirewound about 2 in. tong, with the 
collector tapped in the center and the output tap 
at 1% turns. 

tion with its double collector voltage for 
AM. For two meter relay work and FM it's 
practically ready to go. 

Collector inductance tests were run on 
this unit and the 1 /8th inch coil form 
showed up as at least 98% equal to the No. 
1 coil. Apparently the loaded Q does not 
differ much from one coil to the other. In 
certain cases however, the loaded Q being 
higher might well be needed for selectivity, 
as in a heterodyne vfo, or in tripling. 

A Frequency Multiplier 

Inasmuch as the internal chip in the GE 




+IZV 

o 



33 jv 



,001 



100 a 
TRIMPOT 



0Z6G-I 
RED DOT 



FRONU 
OSC ^ 



50-350 e>F 




.OOi 



^ 



— 



30-35O p? RF OUT 

-^"^AT 50 

MATCH MHj 



LI 




5-80 pF 
TUNE 



t- 



SHIELD 
THIN BRASS 



1- LI, 35T NO 26 OCC ON l/S in OlA FORM 

2- COLLECTOR TAP AT CENTER OF U 

3* OUTPUT TAP AT 4 TURNS FROM COLO 
END ON LI. 



Fig. 8. Layout of rf amplifier. LI = 25 turns No. 
28 dec on 1/8 in. form, collector tap at center 
and output tap at 4 turns from the cold end. 



D26G-1 is a 2N918 type, which is a 
well-known UHF device, it should work 
well as a multiplier, and it did. With some 
change in the base bias, which needs to be 
increased for multiplier service, another 
collector coil for the higher frequencies, 
and changing the oscillator to 48 MHz, it 
took off like a bandit on 96 MHz as a 
doubler with some 50 mW output. After 
several hours of tuning and pruning for a 
tripler stage, 5 V of dc was registering at the 
tuned diode meter on 144 mHz, which is in 
the neighborhood of 15 to 20 mW output. 
The circuit should be considered as tem- 
porary as this is just a "get-acquainted" 
one. It is essentially the same as shown in 
Figs. 7 and 8 with a change in Ll f which is 
now 2 turns, airwound, 10 per inch, 5/8ths 
diameter, tapped at 3/4 of a turn for the 
output, and tuned by C3 only. C2 is left 
out. Be sure and check for 96 and 144 
MHz with an absorption wavemeter as you 
double and triple. 

Note that the collector does not like to 
be tapped down on LI when working as a 
multiplier. 

A 432 MHz crystal exciter will be an 
interesting project, especially with some of 
those 2 GHz experimental microtransistors 
Bill Ashby sent up. 1296 vest-pocket rig? 

Trouble Dept. 

Have a good laugh on me over this one! 
Switching coils around while testing on the 
rf amplifier and multiplier circuits, I went 
back to Six and the power output suddenly 
was very low. Everything tuned nicely, the 
oscillator peaked properly, etc., but there 
simply wasn't that good old 75 mW out- 
put. Only about 25 to 30. Worse still, the 
emitter resistor would not bring up the 
power, it dropped it! I checked the base 
input circuit, the collector tuning, no soap; 
then, not a bright flash but rather a kind of 
dull awakening seeped in. How many times 
I had warned readers to check the fre- 
quency of output circuits with an absorp- 
tion meter. Quick like a bunny (a 65 year 
old one) I reached for the 50 to 150 MHz 
wavemeter and there it was, not 50 MHz in 
the collector circuit but 100 MHz! I had a 
good double but I wanted an amplifier at 






OCTOBER 1974 



29 



that moment. Naturally the emitter pot did 
not bring up the power because a doubler 
needs more bias than a straight through 
amplifier. I had forgotten to solder back in 
the 3 to 30 pF trimmer additional capacity 
across LI and was peaking on 100 MHz, 
Just for fun I looked back through the 
yefars to see when I first worked with a 
multiplier and found it was circa 
1939-1940, doubling from Five to Two 
and a half meters, a little matter of thirty 
years ago. The QTH was Greenwich, 
Conn., and the call was W1LAS, in case 
anyone else is still around from those days. 
So, keep those absorption meters on 
hand and use them. 



One interesting point. Are the elements 
and leads on this device so small that there 
is a smaller feedback capacity than usual? 
Whatever the reason, which Vm going to 
inquire about on some of my next visits to 
the manufacturers, this microtransistor, the 
GE D26G-1, a miniature 2N918 type, has 
been free from self-oscillation to date. 

It appears that pocket size, hand-held 
VHF sets for repeater testing, talking 
through repeaters and just plain QSO*s for 
fun can be built by the amateur home- 
brewer using these devices. Some compo- 
nents need a lot more reducing diets, and 
some are nearly ready right now, as to size* 

. , . Iv 1 LLL 




FT 



THE NANOFARAD 



Carl C. DrumeUer W5JJ 
5824 N W 58th St 
Warr Acres OK 73122 



Our old friend, the microfarad, has 
been with us for a long time. He was 
a handy unit when about the smallest 
capacitance we used was a "triple oh two 
five" grid condenser for a UV-201-A tube. 
We got somewhat disenchanted with our 
old friend when we started talking about 
"six oh point two" as the grid-plate capaci- 
tance of a vacuum, Then we trotted out a 
monstrosity, the micromicrofarad. This 
turned out to be just too much of a 
mouthful to utter in rapid conversation. 
The next step was to revive picofarad, 
which had a wave of popularity in the 
twenties but was quietly dropped when 
someone alleged that the prefix had a 
naughty connotation in a certain unidenti- 
fied language. Picofarad worked quite well, 
but there remained a disconcerting gap 
between it and microfarad that could be 
filled only by using an awkward mu It i digit 
expression such as "fifteen thousand pico- 



farad,*' which left half your listeners won- 
dering just what past of the familiar micro- 
farad you were talking about; or by using 
an equally awkward fraction of a micro- 
farad. 

But, patience, there's rescue at hand. 
It*s the nanofarad, which falls midway 
between the micro- and the pico- and takes 
full care of those puzzling multiples or 
fractions. 

You can get the nanofarad firmly in- 
fixed into your mind and vocabulary by 
remembering a simple relationship: 1000 
picofarad equals one nanofarad equals 
0,001 microfarad. So that "double oh 
two' 1 //F becomes a simple 2 nF and that 
fifteen thousand picofarad becomes a 
much more straightforward 15 nF. Makes 
life much less complicated, doesn't it? Give 
it a whirl. 

« » * TV iJ J J 



30 



73 MAGAZINE 



Lou Macknik W8KBC 
96 Fern wood Ave 
Dayton, Oh 45405 



Frequency Synthesized 

HT-220 



Part 1 



Tlhe very popular HT-220 handi talkie 
has suffered many modifications at the 
hands of amateurs, but none so extreme or 
unusual as this one. With apologies to 
Motorola, I will describe for you my 400 
channel, frequency-synthesized HT-220. 
This article will cover a general description 
of the theory of operation. Part II will give 
the actual circuitry used in the rig. This is 
not a construction article, as such, although 
the experienced builder should have no 
trouble duplicating the work. 

The rig to be described was assembled 
with the knowledge that it would probably 
not work the first time and would require 
much in the way of modifications and 
twiddling- Most of the circuitry was assem- 
bled on plug-in circuit boards which were 
later modified. New circuit boards have not 
been designed at this time. The wise builder 
should place all of the circuitry on one 
board since all of the changes necessary to 
make the gadget work are presented here. 

The idea for this transceiver was born as 
much out of frustration as out of necessity. 
When I first got on 2m FM, the local 34/76 
machine was changed to 16/76 two days 
after I bought a 34 crystal. At that time I 
decided to find out what a synthesizer was 
and how to build one. At the same time I 
was discovering the world of integrated 
circuits. I decided to build the FS-220 
(original, isn't it) using all TTL logic- Nine 



months, later the FS-220 was born (time 
lapse also coincidental). 

The rig was designed to be the ultimate in 
flexibility and to take advantage of the 
low-cost TTL logic now available. It was 
built around a surplus HT-220 circuit board, 
the "universal" type with a T/R relay rather 
than a PTT switch. The basic characteristics 
of the rig are: 

Frequency coverage of 144-148 MHz. 

400 independent receive and transmit 
channels with 1 kHz spacing. 

Digital readout of all frequencies. 

IC memory which stores the receive and 
transmit frequencies and is programmed 
from a Touch-Tone(R) pad, 

TT pad operates normally when not used 
for programming. 

Scanner which may be set to cover either 
50 or 100 frequencies within a 1 MHz range 
(10 kHz steps). 

Powered from 12-15 Vdc (2A receive, 
2.4 A transmit). 

Modular construction for ease in modifi- 
cation and repair. 

Construction cost less than $200 if sur- 
plus houses and junk boxes are well scoured. 



Operation 

Before getting into a block diagram of the 
rig, an example of its on-the-air operation 
should make clear what the above charac- 



OCTOBER 1974 



31 





teristics provide. Let us consider working a 
repeater with non-standard frequencies so 
that no numbers are duplicated. To operate 
on 23/84, the front-panel MHz switches are 
set for 146 MHz operation as indicated on 
the readout (see front panel photograph). 
The CHAN REV switch should be in the 
NORM position, and the SIMPLEX and 
SCAN switches should be off, The OPER- 
ATE-PROGRAM switch is placed in the 
PROGRAM position and the repeater fre- 
quencies are punched into the pad, receive 
frequency first. . .8, . A . .2, . ,3. For those 
who cannot reverse the frequencies com- 
fortably, the numbers can be entered as 
2, .3. -8, .4, .plus any two other characters, 
such as 0..0.. or * *... The OPERATE- 
-PROGRAM switch should now be returned 
to the OPERATE mode. The digital display 
will indicate reception on 146.84 MHz. 
When the PTT switch is depressed, the 
display will change to 146.23 MHz and the 
transmitter will be keyed. For SIMPLEX 
mode, this switch can be placed in either the 
A or B position with the result that the rig 
will remain on either 146.84 or 146,23 MHz 
for both transmitting and receiving. To go 
"reverse-repeater/' simply place the CHAN 
REV switch in the REV position. The 
display will change to 146.23 MHz and you 



can listen to the inputs to the repeater and 
transmit on 146.84 MHz. 

For scanning, the SCAN switch is placed 
in either A for 100 steps, or B for 50 steps. 
In position A, the receiver will scan from 
146.00 to 146,99 MHz in 10 kHz steps and 
the display will follow it. If a signal is 
encountered, the scan will stop and the 
display tells you what frequency you are 
listening on. Two or three seconds after the 
carrier goes away the scan will pick up again. 
With the SCAN switch in the B mode, the 
receiver scans from 146,50 to 146.99 MHz 
in 10 kHz steps. My scanner takes slightly 
less than 5 seconds to scan the upper half of 
the megahertz and is convenient for listening 
only for repeater outputs. When the scanner 
is turned off, the rig returns to the fre- 
quency pair programmed into memory, in 
this sample case, 23/84. 

Any 1 MHz range can be covered by 
setting the MHz switches on the front panel. 
This does allow you to receive on 146.50, 
for example, while transmitting on 144.10, 
or some other weird combination (like 
146.40/147.00 MHz), 

Block Diagram 

Fig. 1 is a block diagram of the complete 
transceiver. The actual frequency synthesizer 



32 



73 MAGAZINE 



UK KHz 



IOMH* 
OSCILLATOR 



9O0O 



(OOKHz 



CLOCK 
GENERATOR 



T 



TIMING PULSES 
TO P/S AND 
MEMORY 




i — * 



PHASE 
DETECTOR 




rN 



FILTER 



LATCH 
1 — 



8 



SCAN 

GENERATOR 



SWITCHED 

BUFFER 
AMPLIFIER 



14- 14 443 
^ 16-16.443 MHz 




DIGITAL 
MIXER 



4.-4.443 
6.-6.443 



146,84 



FROM 

HT-220 

AUDIO 

ro 

TRANSMITTER 

TO 
RECEIVER 



FROM HT-220 SOUELCH 




POWER 
SUPPLY 



Fig. I. Block diagram. 



portion of the rig is almost conventional, but 
does have one feature not ordinarily found 
in amateur gear, a digital mixer. The main 
frequency determining element is a voltage- 
-controlled oscillator (VCO) consisting of a 
single IC Its frequency is controlled by a dc 
voltage derived from a phase detector The 
range of frequencies it can cover is switched 
by changing the LC constants. On receive, 
the VCO covers 14.000 - 14.443 MHz and 
16.000 - 16.443 MHz on transmit. Its 
output is tripled and fed to the HT-220 
receiver for LO injection and also goes 
directly to the transmitter where it is multi- 
plied by nine. The VCO is locked on 
frequency by the .phase detector which uses 
a 1,111 kHz signal as its reference (these 

derived from a 10 MHz crystal controlled 
oscillator. The 10 MHz signal is divided by 
9000 in a fixed divider chain. To provide the 
second input to the phase detector, the VCO 
output is first mixed with the 10 MHz from 
the crystal oscillator to give 4.000 — 4.443 
MHz on receive and 6.000 - 6.443 MHz on 
transmit The mixer used is a digital mixer 
(an fl exclusive OR" gate). Its output con- 
tains just about every combination of the 
two input frequencies, so filters are used to 
select the desired range* The filter outputs 
are divided down to the 1.111 kHz range in 
a programmable divider. During receive, the 
-HN programmable divider is programmed to 
divide by 3600 — 3999. For example, to 
listen on 144.00 MHz, the LO injection must 



be 126,00 MHz (18 MHz 1st i-f). That 
requires a VCO output of 14.000 MHz 
(14,000 x 9 = 126.00). The output of the 
digital mixer is then 4.000 MHz. When this 
signal is divided by 3600 the result is 1.111 
kHz. By the same reasoning, 4.443 MHz also 
gives 1.111 kHz when divided by 3999. For 
transmitting, the programmable divider (^N) 
is set to divide by 5400 — 5799. Since the 
1 st i-f in my HT-220 is on an even megahertz 
(18.000 MHz), the last two numbers in the 
number N always equal the hundreds and 
tens of kilohertz at 2m. During transmit, the 
third number in N always equals the mega- 
hertz. This is a convenience, but not a 
necessity. 777/5 scheme can be easily used 
with hf frequencies such as 10 J MHz with 
only slight changes in the ±N programming 
(see K20AW's article, October, 72). 

Most synthesizers use a formidable array 
of switches to program the ^N counters, I 
wanted to have a digital display and a TT 
pad on the front panel. The thought of also 
including an array of switches didn't appeal 
to me (I really wanted to play more with 
ICs). To get away from the problem, I 
devised the scheme for using the switches on 
the pad to do the programming. The hams 
around Dayton feel that the circuit is the 

i 

product of a deranged mind, but it does 
work and is really quite a convenience. It 
also is good for several minutes of chatter on 
the repeater most any time. 

The switches on the TT pad (not the 



OCTOBER 1974 



33 



DECIMAL BINARY-CODED DECIMAL 
NUMBER EQUIVALENT 








(8) 


(4) (2) (1) 
















1 





1 






2 





1 






3 





1 1 






4 





1 






5 





1 1 






6 





1 1 






7 





1 1 1 






8 


1 









9 


1 


1 





The decimal number is The sum of the rows contain- 
ing a "1 ", Example: 7 equals + 4 + 2+1. The dec 
imal number 82 would be 1000 0010. 



tones) are used to enter the desired fre- 
quencies into the fC memory (hundreds and 
tens of kilohertz). First, the output of the 
pad is encoded in binary-decimal format 
(BCD), The output of the encoder consists 
of four lines. The signals on these lines 
represent the decimal number punched on 
the pad. A logical "0" is equal to OV and a 
logical "1" is equal to about 3.5V, Using 
these zeroes and ones, the decimal number 2 
would come out as 0010, as shown in Table 
I. The BCD equivalent of the decimal num- 
ber goes to a parallel-to-serial converter 
where the four lines are changed to only 
one, Instead of four signals on four lines, the 
output of the P/S converter is on one line, 
with the four signals being transmitted down 
the line one at a time. For the decimal 
number 2, the output of the P/S converter 
would be 0, , ;1 . . ,0, . .0, . .whenever the 2 
button was pushed. The timing pulses re- 
quired to do the conversion are derived from 
the clock generator, A 100 kHz square wave 
is taken from the fixed -^9000 chain and 
used to generate the required pulses. As a 
result, the four signals making up any one 
decimal number are sent down the line from 
the P/S converter at the rate of one signal 
every 10 microseconds. At the other end of 
this line is the memory, It is a left/right shift 
register with parallel input/output capa- 
bility. Mine has a capacity for six decimal 
numbers {24 bits, each signal in a BCD 
number being a "bit")* The bits enter the 
memory from the left With the example 
used earlier for 23/84 operation, let us 
assume that the numbers are punched in as 
8, ,4. ,2. ,3-. When the 8 is punched, it is 



converted into a serial BCD format and gets 
"shifted 1 * into the left-most slot in the 
memory. This takes 40 microseconds. When 
the 4 is punched, ft also gets stored in the 
I eft- most slot in memory, but the 8 has been 
shifted to the right at the same time. After 
the four numbers have been entered, the 
memory contains these numbers (in BCD 
form) as shown in Fig, 1. Notice that the 
output from memory is from the center 
eight bits (center two slots) and is the 
receive frequency. For the other mode of 
entry (six punches), the receive frequency 
is also in the center two slots, but the 
transmit frequency will be in the two slots at 
the right side of the memory. To get the 
transmit frequency all the way over to the 
right requires those two extra "inputs." 

The output from the memory goes to a 
4-line data selector which acts as an elec- 
tronic 4 PDT switch, It selects either the 
output from memory or the output from the 
scan generating section. The output of the 
data selector enters a temporary storage area 
consisting of latch [Cs. The latches do 
several things. First, they hold the current 
frequency while the memory is being pro- 
grammed. This allows you to listen to one 
channel while punching in another. When in 
the scan mode, the latch is the element that 
stops the scan when a squelch signal appears 
from the HT-220 receiver. The digital dis- 
play is fed from the output of the latch (at 
least the hundreds and tens of kilohertz). 

The output of the latch elements supply 
the hundreds and tens of kilohertz necessary 
to program the ^N counters (for example, 
the 84 in 3S84 for reception on 146.84). 
The 3 is programmed by the T/R logic 
(3884) and the 8 is set by the front-panel 
CHANNEL B MHZ switch (3584). During 
transmit, the only difference is that the T/R 
logic sets the first number to 5 (5623) and 
the CHANNEL A MHZ switch sets the 6 
(5623). 

If you have been following this nightmare 
closely you are probably wondering how the 
proper megahertz gets displayed during re- 
ceive. Look back at the examples and you 
will see that for any given receive frequency, 

the -HSl counters must be set to divide by a 
number that is higher by 2 than the received 

megahertz (to receive 146 MHz the ^N must 



34 



73 MAGAZINE 



THE NEW ITC AR-2000 RECEIVER. 
IT'S SO SELECTIVE IT DOESN'T 

KNOW WHAT INTERFERENCE IS. 




The AR-2000 is a completely 

solid-state, dual-channel communications 
receiver with 0*15 uV sensitivity (10 clB 
S + N/N) and selectivity that renders it 
virtually interference-proof (more selective 
than you ever thought a receiver could be). 
Blocking, intermodulation, adjacent- 
channel and crossmodulation rejection 
characteristics are better than any other 
receiver on the market and are typically 
beyond the scope of measurement. 

This plus: modular construction; 
digital frequency readout; all bands (160m- 
10m) in 1 MHz ranges; two independent 
channels for dual receive, transeeive-plus- 
receive or split-frequency operation: 
adjustable IF Passband (to within 100 Hz) ; 



16-pole filter for over 200 dB skirt selec- 
tivity (standard 2.1 kHz BW, shape-factor 
1.4:1) ; adjustable-Q adjustable-frequency 
Notch and Peak Filters; adjustable- 
threshold noise-blanker; Receiver-Incre- 
mental-Tuning; and many other features 
found in no other receiver. Introductory 
price: $1,250 with two-year warranty,* 

The AT-2000 matching trans- 
mitter is completely solid-state, provides 
adjustable output power from 1W to 
175 W, requires no tuning, can be remotely 
operated by the AR-2000, has a built-in 
RF Speech Processor, VOX, Sidetone and 
Heavy-Duty Power Supply. Introductory 
price: $945 with two-year warranty.* 



* War ran ted to be free from defects in materials and workmanship. 
Factory or authorized dealer repairs at no cost to owner for two years* from date of purchase. 



The ITC AR-2000 Receiver and AT-2000 Transmitter- 
performance that challenges your imagination. 

INTERNATIONAL TELECOMMUNICATIONS CORR 

P.O. Box 4235, Torrance, Calif. 90510 • (213) 375-9879 



OCTOBER 1974 



35 



be set to 3500). To get the proper display, a 
simple circuit is used which subtracts 2 from 
the ^N number before going to the readouts. 
The 1 4 portion of the digital display (144.57 
MHz) never changes, so it is permanently 
wired on. This also eliminates the need for 
two seven-segment driver ICs. This scheme 
for subtracting (or adding) will be described 
next month. It can be used with any 
synthesizer to give a digital display without 
thumb-wheel switches. It must be taylored 
for the particular range of -^N numbers in 
use. 

The clock generator provides the neces- 
sary pulses for the memory to store the 
input frequencies. It also causes the memory 
to shift between transmit and receive. As 
described earlier, when programming is 
done, the desired receive frequency is being 
output from memory. When the PTT switch 
is closed on the microphone the T/R logic 
commands the memory to shift right and the 
clock generator sends the memory 8 pulses 
(CHAN REV switch in the NORM position). 
These 8 pulses are sufficient to move the 
receive frequency to the right side of the 
memory and to move the transmit frequency 
into the center two slots. When the PTT 

switch is released, the T/R logic commands a 
shift-left, and 8 pulses from the clock 

generator restores the synthesizer to the 
receive frequency. Everything is just the 
opposite, of course, if you use the alternate 
mode for programming (CHAN REV switch 
to REV and enter transmit frequency first). 
The time required to shift the memory is 
only 80 microseconds. This is negligible 
compared to the 50-100 milliseconds re- 
quired for the phase-locked loop to stabilize 
on the new frequency. 

In the scanning mode the data selector 
picks the hundreds and tens of kilohertz 
numbers from the scan circuitry, rather than 
from memory. The scan circuitry is simply 
two IC counters, a 7490 and a 741 92, set up 
to divide by either 50 or 100. A simple 
free-running oscillator feeds this counter 
with a 10 pps square wave. The output from 
the ICs is taken from the "Q" output of 
each flip-flop, giving the BCD equivalent of 
all integers from 00 to 99, The 74192 can be 
programmed to reset to 5 rather than 0, 
restricting the output numbers to 50-99. 



When a carrier is encountered, a squelch 
signal from the HT-220 freezes the fre- 
quency in the latches. This prevents the PLL 
from changing. The scanner goes on genera- 
ting new frequencies, however. I used this 
scheme because I couldn't get my oscillator 
to start and stop quickly enough to suit me. 



Miscellaneous 

The power requirements of the TTL 
packages are taken care of by single package 
voltage regulators (LM-309) mounted on the 
rear of the chassis. The T/R logic has 
provisions for keying an external relay if 
needed. The audio for creating FM is taken 
from the HT-220 board and fed directly to 
the dc control line of the VCCX The output 
of the TT pad is connected to the micro- 
phone input in standard fashion* 

Next month I will describe the circuitry 
used to accomplish all the good things just 
presented. Many of the individual circuits 
will find applications in other amateur pro- 
jects. 

W8KBC 



Saving Tubes 
n The Galaxy 5 



After seeing how hot those TV-type 
tubes in the final of my Galaxy V Mk 
2 were running - and having one go out 
soon after installation, I decided to install a 
small fan above that section of the rig where 
these tubes are. The fan is a small open 
motor unit with a 4 in. blade, which sells for 
about $2,50 at several of the radio houses. 
Mine is mounted on aluminum brackets on a 
pegboard and is about 2 in. above the top of 
the transceiver. Any of several methods may 
be used for mounting, depending on existing 
surroundings. 

The motor is wired so that the fan turns 
on automatically with the unit so that it 
goes continuously. Since installing the fan 
about a year and a half ago, the tubes have 
not needed replacement and show no signs 

of weakening . 

. , ■ Sam Jamteson W9GQQ 



36 



73 MAGAZINE 



Frank ferome W5Q/Z 

90S Hofoway 

Midwst City OK 73 J JO 





GOVERNMENT 



An organization needs some rules 
with which to govern itself to 
accomplish all the things that it takes 

to keep a good repeater on the air. 
These rules are usually called the 
Constitution and the bylaws. Unfor- 
tunately, a lot of the bylaws never 
seem to get written, or officially 
adopted, and seem to die their own 
natural death. 

The Constitution and bylaws are 
very important to persons other than 
the immediate club members. You 
need to provide copies of the Consti- 
tution and bylaws to at least three 
governmental agencies. These are the 
Federal Communications Commission 
for the repeater groups club station 
license. The Secretary of State for 
your incorporation charter, and to the 
Internal Revenue Service for your 
Code 501 -C Non-profit Organization 
Corporate Income Tax Exemption. 

In addition to your clubs 200 or so 
members, the three governmental 
agencies bog down changes to your 
clubs Constitution and bylaws. Repro- 
duction alone, or plain ink on paper is 
a monumental task, not to mention 
redistribution of the changes to every* 
one that is suppose to have the copies 
and changes. Sure would be nice if 
one complete and thorough Constitu- 
tion and bylaws could be made, 
adopted and submitted to the mem- 
bership and agencies, and never have 
to be changed again. 

The following Constitution and 
bylaws are such an attempt, that is, to 
try to be as complete and all encom- 
passing as is possible, so that there will 
be no big changes looming on the 
horizon within 30 days after you have 
reproduced and sent all that paper to 
all concerned. Here is how it goes: 

ARTICLE I -NAME 

The name of this organization shall be 
ROTTEN RADIO REPEATERS, INC. 
(Obviously, a fictitious name used here for 
explanatory purposes* Since the constitution 
and bylaws need to go to at least three 
governmental agencies, it would be well to 
select a name that is catchy, meaningful, 
somewhat sophisticated. See "Repeater 
Economics" in April, 1973, issue of 73 
Magazine.), a non-profit organization herein- 
after referred to as the Club, 

ARTICLE II- OBJECTIVES 

The objectives for which this Club is organ 
ized are: 

1. To render a public service to govern- 



mental agencies during impending storms or 
severe weather, as well as to assist in disaster 
relief operation and other community tunc 
t ions as required. 

2. To unite the amateur radio operators 
of this area for the purpose of exerting 
effectively a combined influence upon 
matters concerning amateur radio operation. 

3. To promote good operating procedures 
and the exchange of technical information 
and assistance. 

4. To stimulate adherence to a code of 
ethics, both written and understood* 

5. To admonish members to comply with 
existing FCC rules and regulations, 

o\ To be an influence to new amateur 
operators of the area in the operation of 
their station. 

7* To promote good will and fellowship 
among the members. 

8. To further the art of electronics and 
encourage prospective members to parties 
pate in the purposes of the club, 

ARTICLE III -MEMBERSHIP 

SECTION t.< Eligibility for membership in 
the club is set forth as follows: 
Any person is eligible for FULL MEMBER- 
SHIP provided that: 

a. He holds a valid Amateur Radio Opera- 
te r/Sta ti o n I i cense . 

b. He indicates a desire to become a 
member. 

Any person who was included in the original 
organization of this club will be considered 
asa CHARTER MEMBER, 
SECTION 2. To become a member of the 
club, a person who is eligible must furnish 

his name, address, call sign, telephone 
number, and annual dues to the Secretary* 
Treasurer. 

SECTION 3. Honorary Membership may be 
bestowed on any eligible person by a 
majority vote of the members present at any 
regular or special meeting. Honorary mem- 
berships will not be for more than one year. 
Honorary members will not have voting 
privileges. 

SECTION 4. Eligible persons residing in the 
same household may be granted full mem- 
bership privileges by payment of Si, 00 
provided that one member of the household 
has paid full annual dues. All members of 
the same household shall have the same 
anniversary date. 

ARTICLE IV - MEMBERSHIP PLEDGE 

Each member shall pledge himself to adhere 
to the best of his or her ability to: 

a. All applicable FCC rules and regula 
tions* 

b. The requirements of this constitution. 

c. The By laws. 



d. The code of ethics adopted by the 

club, 

ARTICLE V - VOTING PRIVILEGES 

All full members shall have full voting 
privileges providing they are not delinquent 
in their dues and assessments. 

ARTICLE VI -EXPULSION 

Members of the Club may be expelled in 
accordance with such procedure as may be 
established in the bylaws for violation of this 
constitution, violation of the code of ethics 
of the club, or for other conduct which 
would tend to cause discredit to fall upon 
the club or upon amateur radio as a whole. 

ARTICLE VII - RESIGNATIONS 

Any Member has the prerogative of resigna- 
tion from membership in the club and any 
resignation will be recognized and accepted 
when submitted to the Secretary in writing. 
Resigned members will be restored to the 
Club prospective membership list upon use 
of the corporations owned equipments. 

ARTICLE VIM - GOVERNMENT 

The government of the club shall be vested 
in the Officers of the club. The Officers of 
the Club shall be the President, Vice Pres- 
ident, and Secretary-Treasurer. 

ARTICLE IX -MEETINGS 

SECTION 1 Regular meetings shall be held 
as determined in the by-Jaws, A Quorum 
shall consist of 10% of the members. 
SECTION 2. Special meetings may be called 
for any purpose by any Officer of the Club 
who shall preside over the meeting. A 
Quorum shall consist of 10% of the mem- 
bers. 

ARTICLE X - AMENDMENTS 

This constitution may be amended in the 
following manner: 

a. Any proposed amendment shall be first 
presented at any regular or special meeting 
for approval. 

b. Proposed amendments approved by a 
majority vote of the members present at any 
regular or special meeting will be submitted 
to the entire membership for a vote to adopt 
proposals. 

c. The Secretary -Treasurer will mail pro- 
posed amendments in the form of a voting 
ballot to the entire membership. The ballots 
shall include a self addressed envelope 
plainly marked to indicate ballot. 

d. Deadline date for return of the ballots 
to the Secretary -Treasurer will be plainly 
indicated on the ballots and return envelopes 
and must be at least five days prior to the 
nex t r e gu la r meet r ng. 



OCTOBER 1974 



37 



e. The Secretary -Treasurer will open the 
ballots and determine the results of the vote. 
A two -thirds majority vote of the member- 
ship shall be required for approval. 

f. If approved, the proposed amendment 
becomes effective immediately. 

ARTICLE XI - CLUB OWNERSHIP 
RIGHTS 

The Club shall have the privilege of owning 
property both real and personal and the 
right to buy and sell in the club name 
according to the provisions of the bylaws. 

ARTICLE XII - CLUB STATION RIGHTS 

The Club shall have the expressed right to 
establish and maintain a club station and to 
establish operating procedures within the 
privileges granted by the FCC. 

ARTICLE XII! -TRUSTEE 

The position of Trustee shall be filled as 
determined by the bylaws. 

The constitution should show the 
acceptance date and must be signed 
by the Club Officers and two wit- 
nesses. 

The bylaws are where all the action 
is, and they should cover every foresee- 
able circumstances. As mentioned 
before, changes will drive the Off icers 
and Members right up the wall. A 
fairly complete set of bylaws will look 
like this: 
BYLAWS: 

ARTICLE I - CERTIFICATION OF 
MEMBERS 

Upon receipt of application for membership 
in the club, along with the required dues and 
information required, the Secretary- 
Treasurer shall furnish the member with 
certification of membership in the form of a 
membership card. 

ARTICLE II - OBLIGATIONS AND 
PRIVILEGES 

SECTION 1. Club Obligation: It shall be the 

duty of each member to support the club 

with his participation, attendence, time and 

money to the extent that he feels obligated 

to help make a success of the organization. 

SECTION 2. Code of Ethics: Each member 
shall endeavor to abide by the Amateur 

Code of Ethics to the best of his ability. 

SECTION 3. Privileges; All members are 

urged to enjoy alt privileges of the club as 

outlined herein and as offered during the 

existence of this club. 

ARTICLE III - DUES AND ASSESSMENTS 

SECTION 1. Each member is required to 
pay annual dues at the time of joining the 
club and at the end of yearly intervals 
thereafter. The annual does shall be Si 2,00 
which may be paid in the calendar quarters 
by Transient Persons, Students and Senior 
Citizens. 

SECTION 2. The Secretary -Treasurer will 
notify all members of their expiration dates 
and the date which they become delinquent. 
SECTION 3. Any delinquent member maybe 
reinstated at any time. His anniversary date 
will be changed to reflect the date of 
reinstatement if the deliquency exceeds 
three months, providing the delinquent 
member has not used the corporations 
equipment during the delinquent perrod. 
SECTION 4. Family members annual dues 



shall be $1.00. Family members are those 
persons who reside in the same household as 
a full member who is the head of a family. 
All members in the same household shall 
have the same anniversary date* Family 
members shall meet the requirements of full 
members under Article Ml of the Constitu- 
tion. 

SECTION 5. Special assessments may be 
voted by two-thirds of the membership, 
provided however, the entire membership is 
notified in writing the purpose and amount 
of the proposed assessment at Least thirty 
days prior to the meeting at which the 
assessment is to be voted upon. 

ARTICLE IV - ELECTION OF OFFICERS 

SECTION 1. On or about September 1st of 

each year, the Secretary -Treasurer shall 

notify all members of the club that the 

annual election of Officers will be held at 

the regular meeting of the club during the 

month of October 

SECTION 2. The term of office of any 

Officer of the club shall be One calendar 

year, beginning January 1st and ending 

December 3 1st. 

SECTION 3. Any Officer may succeed htrrv 

setf in office, if elected. 

SECTION 4. At the regular meeting in the 

month of October, the presiding Officer will 

accept nominations from the floor. An 

election will be held and the candidate for 

each office who receives the majority vote of 

the members present is elected. Secret baNot 

will be used. 

SECTION 5. Nominees for office shall give 

their approval before becoming a candidate 

for office. 

ARTICLE V - DUTIES OF OFFICERS 

The duties of the Officers shall be such as 
their titles by general usage would indicate. 
Specifically, the President shall preside at all 
meetings. He is an ex-officio member of all 
committees. He is the spokesman for the 
club at all official functions. The Vfce- 
Presidents duties shall be to take over all the 
duties of the President in the absence of the 
President. Me shall have all the authority of 
the President when acting in the Presidential 
capacity. He shall assist the President in all 
activities and purposes of the club. The 
Secretary -Treasurer's duties shall be to keep 
the minutes of each meeting. He will keep an 
accurate financial record for the club. He 
shall file all reports and documents required 
by any governmental agency. He will be held 
personally responsible for the funds 
entrusted to him and give an accounting to 
the club on request. All officers will, upon 
the completion of their term of office, turn 
all properties belonging to the club to their 
elected successors and assist the succeeding 
Officers to learn the necessary tasks required 
for good government of the club. The 
Secretary Treasurer will give an accounting 
of the club members on request, 

ARTICLE VI -TRUSTEE 

The Trustee position shall be filled by Walt 
Hoban WA5XXX, until such time that he or 
the club, by a majority vote at any regular 
meeting, determines that the office be filled 
otherwise. 

ARTICLE VII - DUTIES OF THE 
TRUSTEE 

The trustee shall be charged with the 
responsibility of caring for the physical 



property of the club, as well as acting in the 
name of the club in matters that may require 
official trustee action with the approval of 
the governing body. 

ARTICLE VIM -VACANCIES 

SECTION 1, A vacancy in the office of 
President shall be filled by the Vice- 
President. 

SECTION 2. A vacancy in the office of 
Vice-President or Secretary- Treasurer shall 
be filled by a majority vote of the members 
present at a regularly scheduled meeting or 
at a special meeting. 

ARTICLE IX -COMMITTEES 

SECTION 1, An Executive Committee shall 
be established as a standing committee. This 
committee shall consist of the Vice- 
President^ Secretary -Treasurer, and Trustee. 
Duties of this committee are to act for the 
club under the provisions of Article XI of 
the Constitution and Article XIII of the 
bylaws. 

SECTION 2. Special or Standing 
Committees may be appointed by the Pre- 
siding Officer at regular or special meetings 
that may be necessary* These commiuees 
will function for the club's advantage and 
will be terminated upon completion of the 
assigned tasks, 

ARTICLE X - MEETINGS 

SECTION 1. Regular monthly meetings shall 
be held at a time and place announced by 
the governing body, Notification of the 
membership will be by the best means 
available under the circumstances. 
SECTION 2. Special meetings may be called 
as prescribed by the constitution, 
SECTION 3. Robert's Rules of Order, latest 
edition, shall be recognized as the authority 
of procedures governing any regular or 
special meeting, when not in conflict with 
the constitution and these bylaws* 

ARTICLE XI -EXPULSION 

A member may be expelled from member* 
ship in the club in the following manner: 

a. Proposed expulsion of a member shall 
be openly discussed at regular or special 
meeting and the reasons for expulsion 
explained. 

b. The Secretary -Treasurer shall notify 
the affected member at least seven days in 
advance of the next regular scheduled meet- 
ing, at which time a vote of the members 
will be taken. 

ARTICLE XII - CODE OF ETHICS 

A code of ethics, modeled after the code of 
ethics of the American Radio Relay League, 
shall be approved and adopted, and adhered 
to by the members of this club. 

ARTICLE XIII - OWNERSHIP AND 
TRANSFER OF PROPERTY 

The club may own property as provided by 
in the Constitution, Any purchase or sale of 
club property must have the approval of the 
majority of the members present at a regular 
or special meeting. This does not exclude the 
Trustee from making or authorizing others 
to make repairs to the station equipment or 
any corporation owned property to keep 
said properties fully operational. The oper- 
ating budget of the Trustee will be approved 
by two thirds of the membership present at 
any regular meeting. 



38 



73 MAGAZINE 



ARTICLE XIV - APPOINTMENT OF 
CHAIRMAN AND COORDINATORS FOR 
SPECIFIC TASKS 

The President shall appoint members to 
tasks of chairmanship and coordinators to 
enable this club to accomplish those 
necessary for the good of the organization. 
These job titles will be: EMERGENCY 
COORDINATOR EDITOR of the CLUB 
BULLETIN, PARLIAMENTARIAN, CLUB 
AMBASSADOR, and REFRESHMENTS 
CHAIRMAN. These persons will be directly 
responsible to the Executive Committee and 
will attend Executive Committee meetings as 
invited. 

ARTICLE XV - DUTIES OF EMER 
GENCY COORDINATOR 

The Emergency Coord fnator shall: 

a. Conckict the Sunday Night Round-up 
Contest and insure that proficincy of the 
systems of the corporation is in keeping with 
the public interest. He shall insure that the 
rules of the contest are current and appli- 
cable for various contingencies in which 
Amateur Radio may assist 

b. Maintain a pyramid alert system of 
mobile and transportable radio stations that 
can furfill existing communications require- 
ments for this local area of this club. He will 
insure his own and his replacements availa- 
bility to meet requirements of severe 
weather and disasters in which amateur radio 
can assist. 

c. He will conduct a test of his alerting 
system adopted by the club at noon on 
Saturdays. 

ARTICLE XVI - DUTIES OF EDITOR OF 
THE CLUB BULLETIN 

The EDITOR shall: 

a, Accumulate, edit when necessary, and 
publish news from the national magazines 
for Amateur Radio, 

b. He will canvass the Club Officers for 
material for the clubs bulletin. 

c. He will insure that the bulletin is 
published in a timely manner at the lowest 
available cost and that the size will fit the 
mailing budget of one ounce first class to 
each member, prospective member, 
exchange club bulletins, and alt editors of 
VHF-FM Columns in the national amateur 
radio magazines. 

d, The Editor will also perform all other 
publicity tasks in the best interests of the 
club. 

ARTICLE XVII - DUTIES OF PARLIA 
MENTARIAN 

The Parliamentarian shall: 

a. Decide all questions of order at regular 
or special meetings. 

b. He shall interpret and enforce Robert's 
Rules of Order at all meetings. 

c. Assist the Secretary -Treasurer in main- 
taining the card file of prospective members 
by noting new stations which use the corpor- 
ations equipments and forward call sign, 
name and address, and date that the systems 
were used. 

ARTICLE XVIII - DUTIES OF 
AMBASSADOR 

The Am hassador shall: 

a. Attend all area, regional, and local 
coordinating group meeting scheduled for 
the betterment of VHF-FM* 

b. File written report with the Secretary- 



Treasurer upon completion of scheduled 
coordinating group meetings, 

c. Read the written report at the next 
regular business meeting in the category of 
old business. 

ARTICLE XIX - DUTIES OF REFRESH 

MENTS CHAIRMAN 

The Refreshments Chairman shall: 

a, Provide coffee and donuts at all regular 
and special meetings from the resources of 
the club treasury. 

b. Insure timely preparation of the 
refreshments at all meetings- 

ARTICLE XX - CONTROL STATIONS 

Control Stations for the corporations equip- 
ments will follow guidance established by 

the club station Trustee, The guiding infor 
mat ion will be called the Standard Operating 
Procedures for Control Stations. Control 
stations allowing error or violation to occur 

will be placed in probationary status. Con- 
trol Stations with three or more documented 
errors or violations will be removed as a 
Control Station and will return all corpora- 
tion property to the Trustee. 

ARTICLE XXI - FINES AND LITIGA- 
TION 

All responsible members and prospective 
members and users of the corporations 
owned equipments will file their employer 
information with the Secretary -Treasurer. 
This information will be used to recover 
expenses and fines incurred by violations of 
the Federal Communications Commissions 
Rules and Regulations, This bylaw 
establishes an automatic lien on wages, 
salaries, and other compensation paid to any 
member, user, or other involved third party 
when using the corporations equipments. 

ARTICLE XXII - NON-PAYMENT OF 
DUES BY PROSPECTIVE MEMBERS 

Prospective members and users of the cor* 
pora lions equipments who decline to pay 
the annual dues after six invitations shall be 
remanded to the "LOSERS LIST." This list 
will be prominently displayed at all regular 
meetings of the club. All members are 
discouraged from engaging or contacting 
listed non-paying persons through the cor- 
porations owned equipments. This bylaw is 
void during emergencies as declared by the 
non-paying persons. 

ARTICLE XXIII - HONORARY MEM- 
BERSHIP FOR DEALERS AND OTHER 
COMMERCIALS 

Any person in the category of DEALER, 
COMMERCIAL ENTRANT, or other, and 
any and all relatives thereof shall be 
tendered honorary membership with all 
rights and privileges thereof. This includes 
those persons who are engaged in the radio, 
electronics, and allied businesses as a dealer, 
importer, wholesaler, broker, or manufac- 
turer, and all their relatives. Further defined, 
this shall include those persons who possess 
State Sales Tax Permits and who file Internal 
Revenue Service Schedule "C" in the con- 
duct of their business. Relatives includes 
persons residing in the same household as 
the above subject individuals, 

ARTICLE XXIV -TONE ALERT SYSTEM 

The adopted tone alert system shall consist 
of T000 Hz signal of ten seconds duration, 



This tone will be used to alert the member 
ship of severe weather and disasters through 

the corporations equipments. All members 
are encouraged to use apparatus to intercept 
the tone alert, 

ARTICLE XXV- NAMEBADGES 

All members are encouraged to display the 
clubs adopted namebadge at all meetings and 
functions of amateur radio. The namebadge 
be red and biege with the state emblem. 

ARTICLE XXVI - RECRUITING NEW 
MEMBERS 

The Secretary-Treasurer will send an 
invitation-to join letter to all prospective 
members and users of the corporations 
equipments. He will note on the card file 
cards the dates that the letters are sent. 
Prospective members and users who decline 
to join will be remanded to the losers list in 
accordance with Article XXII of these 
bylaws. Invitation letters wit I be monthly 
and not with the club's bulletin, 

ARTICLE XXVII - SUNDAY NIGHT 
CONTEST RULES 

The Emergency Coordinator will initiate the 
Sunday Night Round-up contest usually 
only during the summer months or during 
the period when daylight saving time is in 
effect. Specific rules as follows: 

a. Contest rules will be transmitted on 
frequency to all participants. 

b. Executive committee will be umpires 
for point subtraction, 

c. Contest area will be restricted to 
Tarzanial County, 

d. The Contest Control Station operated 
by the Emergency Coordinator will record 
starting and ending mileage of participants, 

e. Participants are encouraged to use 
procedures that expedite message handling 
and circuit traffic, 

f. All participants must be mobile 
stations. 

g. SCORING: Participants scores are 
determined as follows: 

Signal 82, accident with injury, 100 points — 
Signal 76, collision with any object, no 
injury, 75 points - Stop signs missing or 
knocked down, 50 points — Signal lights 
malfunction or inoperative, 50 points — 
Power lines on the ground, sparking or 
arcing, 50 points — Fire, building, grass or 
smoke hazard, 25 points — No barricade at 
manhole cover off, excavation, etc., 25 
points — Stalled or illegally parked vehicle in 
traffic, 25 points — Trees, weeds, or 
vandalism covering traffic signs, 25 points - 
Warning flasher lights no working, 25 points 
— No barricade at chughole in traffic lane, 
10 points — Debris, glass, gravel, tree limbs, 
trash in street, 10 points — Loose domestic 
animal, horse, cow, dog, 10 points — Dead 
domestic or wild animal in traffic lanes, 10 
points — Loud outside burglar alarms, 10 
points — Street marker sign down, missing, 
or vandalized, 10 points — Natural gas odor. 
5 points - Mileage, points per mile 5, 
SUBTRACTED POINTS: 
Improper location transmitted -25 — 
Doubling over the frequency in use -25 — 
Improper procedure -10 — Low audio 
quality -5« 

h. Contest winner will be the mobile 
station with the highest point total 

L All contest point standings announced 
at conclusion of contest. 



OCTOBER 1974 



39 




^^™ 



j. Contest period will generally be two 
hours, from 7PM to 9PM, 

k. Contest session automatically 
terminated in the event of dtsasler. 

ARTICLE XXVIII - AMENDMENTS 

These by taws may be amended by a majority 
vote of the members present at any regular 
or special meeting of this club. 

Having a proposed set of Constitu- 
tion and Bylaws does not mean that 
you will be able to get them adopted 
by the membership. The experience of 
the local club indicates certain areas 
of question which result in much 
haggling. A big problem area seems to 
be the reasonable amount of member- 
ship that constitutes a Quorum. 

A big argument for having 10% as 
the quorum is simply because that is 
what it is in the LL5, House of 
Representatives. Just as sure as you 
make it larger, there will always be 
some major event that will conflict 
with a very important meeting date. 
The major event may be anything 
from the county fair to the new TV 
show season. Keeping the quorum 
small probably results in larger atten- 
dence at the meetings since more 
persons wit) attend just to make sure 
that a minority will not run away with 
things of the corporation. As you can 
see, big haggling area is needed when 
it comes to discussions about the 
quorum 

Another head clunking deal is the 
honorary memberships for the dealers 
and commercial entrants who are in 



it 



it 



the radio business, A likelihood exists 
that these persons may very well be 
some of the biggest supporters of the 
local repeater, however; they are also 
the same persons who the lobbyests 
can get to should the pressure be 
increased to "end amateur radio." 
Recent magazine articles have dealt 
with this subject with articles such as 
Amateur Radio's Last Year/' and 
Sneaky Proposal/' It may cost your 
club a lot of money from the stand- 
point of free membership, but that is 
probably better than no club at all for 
amateur radio in two or three years. 
Much teeth gnashing can be caused 
by the Control Station bylaw. The 
question is, just how do corporations 
handle this multi-headed monster of a 
person acting in behalf of the Trustee 
who in turn is designated with respon 
sibility of the corporations interests? 
Catch on to that snakey deal. The 
Trustee is appointed by the club. 
Every thing he does is in accordance 
with the FCC rules and regulations. 
That includes appointment of the 
control stations. The event of a con- 
trol station making quantities of boo- 
boos and getting cited more than once 
must be covered in the bylaws. Such a 
bylaw may make it difficult to get 
volunteers to act as control stations, 
but that simply is the breaks of the 

game and another reason to write 
your Congressman about the un- 
reasonableness of the FCC. To remove 
a control station and add a new one 
costs S8.QG\ Cannot allow that to 



happen too many times in dhy one 
club. 

A similar problem area covered in 
the bylaws is concerned with fines and 
litigation. Hopefully, no repeater 
group will ever get into a four way 
lawsuit. This would be a simple case 
of perhaps profanity or broadcasting, 
and involving some user of the corpor- 
ations equipment, the Trustee, a con- 
trol station, and the Feds. The Federal 
rules and regulations seem to put the 
monkey on the Trustees back, but in 
reality, it will always be the user who 
will actually committ the violation, 
and do so quickly in a manner that 
the control station doesn't have time 
to hit the kill button. Simply, the 
corporation here is not ready to pay 
some one's fine. The corporation was 
not organized to protect the hard case 
or semi-nit wit, but to enable opera- 
tion of a repeater. 

It has already happened here and 
likely has in other places. The circum- 
stance was a cold winter day and a 
hard to start auto. The unknown 
subject apparently had two radio 
equipped autos, and had the woman 
of the house, likely unlicensed, oper- 
ating the vehicle in tow. Needless to 
say, when she did not operate the 
brakes at the proper moment, there 
was much profane advice and direc- 
tions given. 

All the luck in the world to you 
and yours in your Repeater Govern- 
ment. 

, . .WSOJZ 



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40 



73 MAGAZINE 



THE HEAT 



Kent A. Mitchell W3WT0 
1 004 Mulberry Avenue 
Hagerstown MD 21740 




HWA-202-1 AC Power Supply 



The HWA-202-1 power supply is 
intended for use as a companion unit 
for the Heath HW-202 2 meter FM Trans- 
ceiver when that rig is operated at a fixed 
QTH where ac power is available. However, 
the features of this supply also make it a 
very fine general duty, 12 V, 2 ampere 
source for operating miscellaneous solid- 
state receivers, converters, amplifiers or 
experimental circuits on the bread board. 

Output voltage is internally potentio- 
meter adjustable from 10 to 15 V and Is 
completely regulated within V/i% from no 
load to full load (2,2 amps). In addition to 
conventional circuit breaker protection, the 
unit is electronically protected from current 




This Photo shows diode D4 with cathode 
band painted on wrong end. 



overload (short circuit) by the integrated 
circuit sensing arrangement which is the 
heart of the regulator circuitry. Voltage 
from the ac plug up to the dc regulator is a 
conventional transformer-diode bridge recti- 
fier capacitor filter circuit. . .but between 
this point and the output connector is a 
large regulator transistor whose emmitor — 
collector path is in series with the power 
supply's load. The base of this transistor is 
biased by the IC output which is determined 
by its comparing a zener diode reference 
voltage with that of the output voltage. 

Assembly of the kit is very simple and 
can be accomplished in less than 2 hours. 
Most of the components are mounted on a 
small etched circuit board and this accounts 
for the rapid assembly. 

Upon completion of my power supply, I 
plugged into a nearby ac receptacle, placed 

the unit's power switch to the ON 
position- , .and promptly popped the circuit 
breaker. This bordered on discouraging. I 
rechecked the wiring. Nothing. I checked for 
cold or bridged solder joints. Nothing. I 
checked the marked polarity of the electro- 
lytic capacitors and diodes. Looked OK, I 
rechecked the wiring. Nothing. I unsoldered 
the transformer leads and measured resis- 
tances in a search for shorted windings. 









OCTOBER 1974 



41 









Checked OK. I rechecked the wiring. Noth- 
ing, I removed the regulator transistor and 
made emitter to base and base to collector 
resistance readings. Read OK. I rechecked 
the wiring. By now the power supply was 
almost back in the unassembled condition 
that I had started with two hours earlier! 
Finally, while checking the front-to-back 
resistance of the diode rectifiers, I 
discovered a curious thing. . .one of the 
diodes had the cathode band painted on the 
wrong end! After turning the diode around 
(and reassembling the power supply), every- 
thing worked as advertised. In all of my 
years in electronics, this was the first time 
that I ever encountered a mismarked com- 
ponent, and it was certainly not the fault of 



the Heath Company, but it is something to 
look for when almost all else fails. 

As a final check prior to placing the unit 
in service, I connected an oscilloscope to the 
output leads and, with the vertical sensitivity 
at .OSv/Cm, was unable to detect any ripple 
component of the dc voltage. Under load, 
using an HW-202 in the transmitting mode, 
less than 10 millivolts peak-to-peak ripple 
was observed, which for practical purposes is 
negligible. 

Priced at $29.95, the HWA-202-1 rates a 
"good buy" as an accessory unit for the 
HW-202 transceiver, which it matches in size 
and style, and as a well regulated 12 V 
source for the ham shack. 

. . .W3WTO 



HOW TO BE SURE 



THAT HAM RADIO 



Gabe Gargiulo WA1GFJ 

1 7 Whitney Street 

East Hartford CT 06118 



HAS A FUTUR 



The best way to protect something is to 
get someone powerful to look after it. 
The fact that you, the ordinary person, want 
to safeguard amateur radio means nothing. 
The only way to guarantee a future for ham 
radio is to get business behind it. Look at 
what the electronics manufacturers are doing 
to keep and expand CB! 

Big business is not going to care one hoot 
about ham radio if you tell it how great and 
wonderful ham radio is, or what worthwhile 
things are accomplished on the air. They will 
begin to care only if the outlook is good for 
profit. 

Yes money — the root of all evil. That is 
what will make company presidents sit up 
and ask, ''What in hell is ham radio?" If they 
realize that there is money to be made on 
the hobby of those crazy nuts, they will take 
pains to protect it. Money will be spent to 
influence legislation on our behalf. Subtle 
pressures will be felt by government officials 
at all levels. Better yet electronics manufac- 
turers will continue to produce ham gear at 
competitive prices. They will promote ham 
radio and introduce young people to it. All 
this will expand the hobby and cause it to 
grow. 



Nice — but it won't happen unless some 
money starts to flow into the treasuries of 
the makers of ham gear. This means that 
you, Joe Ham, must get out and buy. 
Purchase ham gear. Buy new equipment. 
Don't spend your money on cigarettes. 
Forego the luxury of a new air-conditioned 
car, Instead, buy a quad and a 40 foot 
tower. 

Buy! Buy new transceivers, receivers, 
transmitters, antennas. Get into two meter 
FM and ATV. Get that scope you always 
wanted. When your wife asks where all the 
money is going, tell her that it is to insure 
that ham radio has a future, and to protect 
your investment in all that expensive equip- 
ment. Remefnber, you arent wasting money 
or indulging yourself — youYe only protec- 
ting your investment. Besides, you're helping 
to creat jobs in the electronics industry. 

How can you resist now, knowing all the 
benefits of buying more radio gear? Just 
thumb through this magazine and you \\ find 
page after page of luscious goodies just 
waisting to be bought. Protect your invest- 
ment. Be sure ham radio has a future. Buy. 
Buy, Buy. 

. . .WA1GFJ 



42 



73 MAGAZINE 



A 



Simple 



Peter A. Stark K20AW 

P. O, Box 209 

ML Kisco NY 10549 



5V 



Power Supply 



For Digital Experiments 




Now that some 7400-series TTL 
(transistor-transistor-logic) digital inte- 
grated circuits are available for as low as 20^ 
apiece digital projects are getting more 

popular among hams. Here's just the right 
power supply to make your digital experi- 
menting easier. 

As shown in Fig. 1 , the supply consists of 
a simple bridge rectifier, fairly heavy fil- 
tering with two 2200juf electrolytics, and 
regulation with an LM309K integrated cir- 
cuit regulator. As shown in the photos, the 
LM309K is mounted on an aluminum heat 



2A 

50 PIV 
DIODES 





2A 
DIODES 



LM3C9K 
REGULATOR 

2 



OPTIONAL 
*3.5V 



POWER 
SWITCH 



x 




GROUND 



3 (CASES 




LM309K 
BOTTOM 
VIEW 



Fig, 1 



sink right on the case (the ICs case is 
grounded so no mica insulators are needed). 
With such a heat sink the circuit will provide 
up to 1a at 5V. With the \C mounted just on 
the case, but without a separate heat sink 
with fins, the maximum current output will 
be somewhat less, but probably still above 

S4a. 

The secret of the circuit, of course, is the 
regulator IC Not only does it provide 
excellent regulation and practically eliminate 
any ripple on the output, but it is also 
short-circuit proof — you can short the 
output of the supply and no harm will be 
done. It also shuts itself off in case its 
temperature gets too high, in other words, 
no damage will be done if you skimp on the 
heat sink — you just get less output current 
before it shuts off. 

The 5V output is perfect for 7400-series 
and other TTL ICs, as well as most DTL and 
ECL circuits. Since RTL ICs need only 
about 3.6V, you can add an optional output 
for these ICs by just adding two diodes and 
one more electrolytic. 



OCTOBER 1974 



43 



■R 



K-ENTEJ"" 



qC^ 




PRESCALER MODEL PD-301 

$55.50 plus $1.50 postage 

Model PD 301 is a 300 MHz pnescaler designed to extend the range of 
your counter ten times, This pm scaler has a built in preamp wth a 
sensitivity of 50 mV at 150 MHz. 100 mV at 260 MHz, 175 m Vat 300 
MHz. The 95H90 scaler is rated at 320 MHz, To insure enough drive for 
all counters, a post amp, was buili in. The preamp has a self contained 
power supply regulated at 5,2V * Q8V (Input 50 Ohms. Output Hi Z) 

All prescalers are shipped in a 4" by 4" by T!V cabinet. All are wired 
and calibrated, 



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Fig. Z Inside the K2QAW power supply. 

To reduce power supply feed through of 
logic signals from one circuit to another, 
place the 1 OOfif and Jjuf capacitors as close 
as possible to the two output terminals, and 
use short leads. In addition, don't forget that 
TTL ICs generate very short spikes on their 
power supply lines, and therefore you will 
need additional bypassing inside your cir- 
cuitry itself. Every four or five ICs (at the 
most) should have their own OJ or G.QIjuf 
disk capacitor connected directly from the 
+5V line to the nearest ground, using the 
shortest possible leads. These additional 
capacitors should be as close to the ICs being 
filtered as possible. In really severe cases, 
you may have to connect these capacitors 
right at each IC 

Chances are good that you won't need a 
bigger supply than this; we've used it to 
power a frequency counter with over 30 
TTL ICs which only took slightly more than 
Via. Not many projects will ever need more 
than 1 a. But if you do need a bigger supply, 
don't try paralleling the LM309K regulators 
to increase their current capacity, since they 
will not share the current equally. The best 
bet wouid be to make several separate 
supplies, which share only a common trans- 
former, rectifier and brute-force filter (at 
least 4000jif per ampere). Each output 
would then be separately regulated, and 
would drive a separate part of the circuit. 

. . . K20AW 



44 



73 MAGAZINE 



F. H. Ryder VE1AIUGT 
Bsc M. Eng. P. Eng. 
(M) 1EEEC. Eng. F1EE 
VE1A1L, VE1GT, XM65-2239 




HE WET NET 



The Saint John River rises in the State of 
Maine, and flows half of its total length 
northward to the very tip of Maine, then 
turns southward and flows through the west 
and central part of the Canadian Province of 
New Brunswick. 

There are no flood control dams on the 
Saint John River in northern Maine, a 
conservationist's paradise, and consequently, 
by the time a large rainfall In Maine reaches 
New Brunswick, little can be done except 
"run for the hills." This can be done quite 
easily on most stretches of the river, with 
one exception; just east of the capital city of 
Fredericton, the northern bank of the river 
flattens into a flood plain which forms the 
market garden area of central New 
Brunswick. Slightly more than 1000 
dwellings and about 1 50 farms are located in 
the 40 mile stretch of interval land. Most 
years the St. John River floods its banks and 
gently submerges the area. When the water 
subsides the further enriched thick black soil 
will grow most anything — fast! 

On the last weekend of April 1973 such a 
gentle innudation was taking place, however, 



in Northern Maine and New Brunswick the 
equivalent of an additional eight inches of 
water lay in the woods in the form of snow. 
On Saturday, April 30, Northern Maine and 
Northern New Brunswick experienced in the 
order of 2Yi inches of warm rain which 
would have been bad enough in itself but it 
also melted the snow and to repeat a famous 
saying, "then the fun began.'* Within four 
days, the previously recorded record flood 
level in Maugerville — Sheffield set in 1887 
was exceeded by some three feet and pre- 
viously accepted levels of preparedness for 
flooding were proven to be inadequate. 

The Emergency Measures Organization 
(EMO) here in Canada has of recent times 
been giving more serious consideration to 
civil emergencies of reasonable magnitude 
and probability. In early 1973, the New 
Brunswick Amateur Radio Association was 
asked to define what sort of communica- 
tions capability could be provided in an 
emergency and in due course a brief was 
prepared and presented to EMO, 

Little was it then realized that less than 
three months after completing that report, it 






OCTOBER 1974 



45 






would form part of the discussion papers 
during the organizational meeting of a 
massive flood rescue and relief operation. 

The Flood Forecasting Task Group is a 
joint effort of Federal and Provincial Depart- 
ments of the Environment and N. B, Power, 
an electric utility with hydro generating 
stations on the river. This year the task 
group was located in an office of NL B. 
Power and fortune dictated on that wet 
Saturday evening that I visit the task group 
and come upon the organizational meeting 
of the rescue operation. In due course, the 
opportunity was given to define once again 
the services that could be provided by Radio 
Amateurs and within one hour the "Wet 
Net" was in operation on 80 meters with 
VE1TC, BM and ACA alternative as net 
control and on two meters a station was set 
up in one of the N. B. Power offices taken 
over by EMO for the emergency operation; 
this gave us a completely independent com- 
munications link with the EMO office 
should the telephone circuits become inade- 
quate. 

It was emphasized to EMO officials that 
our automatic repeater VE1GT gave solid 
coverage of the low lying area and that we 
could assure direct communications with 
their field staff anywhere in the area, As a 
test of this VE1 AJT (now AKT) a hand held 
unit was dispatched with a helicopter patrol 
unit early Sunday morning and provided the 
EMO official doing the patrol with commun- 
ication directly with his confreres in the 
office. 

On Sunday morning the record flood was 
still only a forecast and the water in Mauger- 
vilfe — Sheffield was as yet some feet below 
previous record levels. A road patrol was 
then mounted using a large utility vehicle, 
with VE1 AEK, (now HL) in operation. 

N. B. Dept. of Agriculture representatives 
were on board and the purpose of the patrol 
was to advise each farmer of the impending 
increase in the water level and to evaluate 
the situation of each so that subsequent 
rescue operations would be as effective as 
possible. The patrol barely made it back, 
with water well up on the tires and sitters on 
the front fenders peering down through the 
water to ensure that the driver stayed on the 
road. 



The rest of the day was spent in prepara- 
tion for rescue by means of scows, barges, 
ferries and military amphibious vehicles. 

There is a saying "Nothing like good 
service is so effective in increasing the 
demand for that service/' I won't say how 
good our service was but we began to get 
swamped with demands. Hand held units 
were required on board the rescue craft and 
base stations were required at the mar- 
shalling points where livestock was to be 
transferred to transport trucks. This was 
obviously beyond the resources of 

Fredericton Amateurs and a call for two 
meter equipment and operators for 24 hour 
a day operation was made on 80 meters. 
And did it come? You bet! A contingent of 
9 from Saint John led by Ken VE1 AVA and 
one of 6 from Moncton area led by Ron 
VE1SH and Reed VE1NU, who brought 
walkie-talkies, Don VE1 DK came 300 miles 
from Truro, Nova Scotia to lend a hand; this 
gave us a total of 33 operators. Ken and Ron 
covered the marshalling points at Burton, 
across the river from Maugerville and the 
others manned the boats. The object being 
that anyone requiring assistance could get it 
with the least possible delay. A battery of 
telephones had been installed in the EMO 
temporary headquarters and from this co- 
ordinating centre rescue craft were dis- 
patched from the Burton marshalling point 
by amateur radio. The net also proved of 
value to the rescue craft when one got both 
propel I ors tangled in a barbed wire fence and 
another lost its engines and grounded. 

I would be remiss in not mentioning the 
part played by the several GRS (CB) clubs in 
support of the operation. Base stations were 
in operation both at Burton and the EMO 
Headquarters on a 24 hour basis and many 
CB equipped small patrol boats made reports 
of conditions. Many of the transport trucks 
hauling livestock were CB equipped and 
were more effectively dispatched than would 
otherwise have been possible, particularly as 
the scows would often miss their scheduled 
landing wharf and be swept downstream to 
the next one. Much co-ordination was 
needed to get the trucks and the scows to 
the same wharf. 

The rescue operations were complicated 
by the fact that to reach the barnyards 



46 



73 MAGAZINE 




Rescuing a reluctant cow. 



rescue craft had to cross over the' highway, 
covered by only 3 to 4 ft of water and 
consequently, only very shallow draft vessels 
were of use. The operation continued 
through Monday, Tuesday and Wednesday, 
dawn to dark; navigation on the river after 
dark was too risky. 

Government offices and the legislative 
buildings also suffered from the flood, and 
we soon found that the Premier's temporary 
office was just down the hall and he, as wejl 
as various ministers, came in from time to 
time to inquire about various things and 
were briefed on the role of amateur radio in 

the emergency effort, in addition to getting 
the answers they came for. 

On Tuesday night the 200 prize cattle of 
Gerald Hoogendyk stood on dry land with a 
foot to spare. On Wednesday morning, they 
stood in icy water belly high when the 
Second Field Artillery came to take them 
out By now these cows were in panic and 
the sound of roaring motors as the soldiers 
executed an aquatic roundup was drowned 
out by bawling cows and calves. Often the 
men were obliged to jump into the icy 

waters to assist an animal to get on board 
the scow. At Waterbury's farm, having 
rescued the 30 cows from the corral, one 
brave lad went in to get the 1800 lb, bull 
and was promptly thrown out through the 



fence, Doug Nielson, the EMO Rescue Co- 
ordinator, 6*4", 200+ lbs, then went in and 
after running the bull around the corral 
several times made for the scow. Both he 
and the bull got on all right but couldn't get 
stopped; two cows and several soldiers were 
pushed right over the other end of the scow. 
A helicopter patrol later reported seeing a 

scow crossing the river with 30 cows and a 
group of soldiers crowded up in one end 
while a large bull glowered at them from the 
other. 

At Henry Shuttenbeld's farm, there was 

another problem of slightly different dimen- 
sion: 300 pigs, and time was of the essence 
in this evacuation because pigs can't stand 
cold water very well. It was the same thing 
all over with the action speeded up to almost 
comic proportions to the tune of the high 
pitched squeal of the pigs. 

Communications by now had been 
worked down to a simple routine, with 
operation on 94 simplex between the rescue 
craft and Burton, and via VE1GT for other 
operations. On Thursday morning we were 
advised by EMO that since things were now 
tapering off they wished to rely on the 
commercial and military communications 
systems for the balance of the Maugerville — 
Sheffield operation. 

The crest of the flood was now proceed- 






OCTOBER 1974 



47 



^« 



— < 



ing towards the City of Saint John on the 
south coast of New Brunswick and both the 

EMO and the radio amateurs turned their 
attention to this city, 70 miles south of 
Fredericton. The Saint John EMO office had 
limited telephone access and this was soon 
jammed so the two meter station of Dick 
VE1 ATG was set up and a relay maintained 
through the 80 meter Wet Net, Phone 
patches proved useless because of jammed 
phone lines but a 2 to 80 meter patch made 
by alternately holding speaker to micro- 
phone enabled a direct relay at one point 
when such was needed to precipitate action. 

By Friday noon, the danger of further 
flooding was passed and all amateur opera- 
tion in support of EMO ceased. 

To emphasize the magnitude of the oper- 
ation, some 1500 people were temporarily 
relocated and 1200 cattle, 400 pigs and 20 
horses were rescued with the loss of only 

four and with no loss of human life or major 
injury. 



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In conclusion, there are several observa- 
tions on emergency communications that 
can be made on the basis of this operation: 

1. The amateur is there to provide a 
communications service and not to involve 
himself in the operation, that's the problem 
of the emergency officials. Just pass the 
traffic and give them direct access when they 
need it to sort out a difficult problem. 

2. The most ineffective repeater has a pair 
of ears and a mouth. Traffic handling is one 
area where hams as well as CBers alike fall 
down; for this reason, and my observation 
that emergency officials seem to prefer to be 
able to talk directly to their counterparts, I 
recommend that when such a need is evident 
HF-VHF and CB patching be used where 
repeater links do not exist. 

3. Frequencies and repeaters used in the 
emergency must be kept free of chatter. It 
gives a terrible impression unless the stations 
interfacing with the emergency organization 
uses earphones and net control quiets every- 
body down while the emergency officials are 
at the mike. This is hard to do on VHF, 
worse on HF and well nigh impossible on 
CB. 

4. Patrol vehicles must report what they 
see, without assumptions, or opinions, and 
do it briefly, clearly and slowly. Many a wild 
goosechase has been precipitated by the 
embelleshment of report. Checking up on 
such reports is easier to do when the 
reporters can be grilled directly rather 
through a number of relay stations. 

5. It is my opinion that in subsequent 
emergencies of this magnitude the use of 
VHF and repeaters is a must. Means must be 
found to erect temporary repeaters during 
such emergencies in areas not permanently 
served and to link them on VHF full time or 
patch them on HF when necessary, to the 
emergency control centre, HF has its place 
for long distance communications and 
should not be cluttered up with local com- 
munication activities. CB has the advantage 
that there are many portable and hand held 
units in service today but range must be 
limited to distances such that the desired 
signal will not be swamped in the ever 
present interference. 

...VE1AIL/GT 



48 



73 MAGAZINE 



320 



340T 



381 



550 



r 40O ieriesj*nee Schedule 

20 HOB 30 

.30 S 05 50 

.30 06 .40 

,50 LQ6 .BO 

.20 07 40 

08 .20 



.30 
20 H08 
30 09 

.20 TO 
30 H10 
SO L10 
20 S10 



Pnce Schedule 

P«, V Reg. (Super 723) 

HI performance Am pi. 

Voltage follower 

Negative Regulator 

Voltage Regulator 

Voltage Comparator/Suffer 

Op Amp (Super 7411 

Micro power op Amp. 

5V Regulator {200 MA) 

5V Regulator (1A) 

Voltage follower Op. Amp. 

Hi performance Voltage 
Comparator 
0V fvegattve Regulate 
2V Negative Relator 
2V Negative Regulator 
5V Negative Regulator 

Precision Timer 

Quad Op. Amp r 

Quad Comparator 

Pos V Reg 

(+5.6,8,12,15,13,24 V) 

Pos V Reg 

1 1 5.63.12,15,18,24 V} 

Dual Peripheral Driver 
Dual Penpharal Driver 
AGC/Squelch Amp. 
Integrated RF/IF Amp. 
AF ■ IF strip - detector 
AM/FMI SSB strip 
AM/FM/SSe IF Video Amplifier 
Poi Volt Regulator 
Dual 2VV Power Amp 
2 Watt AudfO Amp, 

6WAudiO Amp. 

Low Notse Duel Pre Amp 

Low Noise Stereo Pre Amp 

Precision Voltage Regulator 

Timer 

Phase Lock Loop 

Function Generator 

Tone Decoder 

13 .75 L30 30 48 

14 2,00 H30 .30 50 
516 .50 32 .25 H50 

16 .40 37 M S1 

17 .40 38 .36 L51 
20 -20 39 50 H51 

H20 .30 40 20 H52 

.30 53 

.50 H53 

1.00 54 

90 H54 

150 L54 

1.50 L55 

1.50 H55 

90 60 

1.50. H60 

1 50 H6T 



Ifrand New CMOS 

74COO .50 

74CO? ,50 

74C04 .75 
74C10 50 

74C20 .50 
74C30 50 



20 

30 

50 

,50 

74C42 

74C73 

74C74 

74C76 

74CA3A 

74C85 

74C86 



.40 42 
50 L42 
.40 43 
40 44 

.40 45 

40 4« 
.20 47 

74C89 

74C95 

74C107 

74CI51 

74C154 

74C157 

74C160 
74C161 



T05 

T05 or mini 

T05 

T05 

T05 

T05 

TOBor mini 

T05 

TO-5 
TO 3 

T05or mini 

T05 or mini 
T03 



TO-22 

Dip 

Mini 



2.00 



1 



747 



12.75 
350 
1 60 
300 
5.00 
2.50 

£88 



74C162 
74CT53 
74C164 
74C165 
74C173 
74C174 
74C192 
74C193 



74C19S 
74C901 
74C902 

74C903 
74C904 

80C95 

BOC97 
CD4001 



3070 
3071 
3072 

3075 

3900 

3905 
4250 

5070 

5072 

75450 

75451 

75452 

75453 

75454 

754&1 

75492 

75493 
75494 

1.00 92 1 

.40 93 I 

.60 L93 1 

.80 94 1 

80 95 1 

1.00 L95 1 

1.50 96 1 

2 50 L98 3 

35 100 1 

.50 t07 

.80 109 

5.00 S1 12 1 

3.00 SH3 i 
1 00 5114 ; 

1.25 121 

1.00 9601 

1 25 122 

Cd4002 

Cd4006 : 

CD4007 

C04008 '- 

CD 4009 
Cd4010 

) CD4011 
CD4012 



RF - IF Amp. 

Op Amp. 

Voltage Comparator 

Dual Pitt. Comparator 

V Rcgutator 

liijii u mentation Op ArtiR 

Video Amp 

Comp Op Amp. 

Dual 741 Op Amp, 

Freq.Ad], 741 

Stereo Pre Amp. 

FM Multiplex Stereo Demod, 

FM Multiplex Stereo Demod. 

FM Multiplex Stereo Demod, 
Stereo Demodulator 
FM De lector /Umiter SVAudioPnun 
Dual Differentia* Comparator 
High Voltage Op Amp 

Puat Comp, Op Amp. 

FM Detector & Limtrer 

FW Detector & Limiter 

TV Automatic Fine Tuning Circuit 

TV FM Sound System 
Chroma Subcarrier Regenerator 
Chroma IF Amplifier 
Chroma Demodulator 

F M Detector LMTR and 
Audio Pre Amp. 

Quad Amp. 

Precision Timer 
Programmable Operational 

Amplifier 
Chroma Subcarrier Regenerate i 
Chroma Demodulator 
Dual Peripheral Driver 
Dual Peripheral Driver 
Dual Peripheral Driver 
Dual Peripheri* Drrver 
Dual Petjph*ral Driver 

Quad teg driver for LED readout 
Hex digit driver 
Four Segment LED Driver 
Six Digit LED Driver 



123 l.C 

9602 .1 

125 
126 F i 

132 3.( 

S140 1.f 

141 1.3 

145 U 

150 U 

151 l.C 

152 3< 

153 l.t 
S153 1-! 

154 1! 

155 U 

156 If 

157 T.I 
CD4013 
CD4014 
CD4015 
CD4016 
CD4017 
CD401B 
CD4019 
CD4020 



7 126 

7 1,50 

8 200 

1;S0 
1.50 

1 2.00 

2 1 50 

3 1.50 
i 2,00 
I 2.50 
i 2.00 

> 2.50 

> 1 50 

y 3.oo 

I 2.00 

i 250 
( 2.00 

CD4021 
CD4022 

CD4Q23 
CD4024 
CD4025 
CD4027 
CD402&" 
CD 4030 



TD6 




40 




T05w 


Dip 


30 




TOSor 


Dip 


.X 




T06or 


Dip 


.30 




T05or 


Dip 


.60 




Mini 




2.25 




Dip 




1.25 




T0B, Mini, 






or Dip 


.40 




TOSot 


Dip 


.80 




Mini 




.40 




Dip 




.75 




Dip 




1.00 




Dip 




1.50 




Dip 




.75 




Dip 




250 




J Dip 




100 




Dip 




90 




TO-5 




395 




T05o* 


Mini 


.70 




Dip 




90 




Oip 




.90 




Dip 




.75 




Dip 




-60 




Dip 




1-35 




Dip 




1.35 




Dip 




1.35 




DIP 




.70 




DIP 




.70 




Mini 




L40 




Dip 




2.25 




Dip 




50 




Oip 




,20 




Dip 




.80 




Mini 




.40 




M<n< 




40 




Mini 




.GO 




Mini 




.80 




DIP 




1.25 




OIP 




K25 




Dip 




140 




Dip 




1.50 




S174 


300 


L192 


200 


176 


2,00 


193 


150 


S175 


3.00 


L193 


2.00 


176 


1.00 


194 


1.50 


177 


F.00 


195 


1 (in 


178 


3.00 


LI 95 


1 50 


179 


3,00 


196 


2.00 


180 


100 


197 


200 


181 


3.00 


198 


2.00 


T82 


1.00 


199 


2.00 


184 


2.00 


200 


7.00 


185 


200 


S200 
251 


999 

1.75 


189 


3.00 


284 


4.25 


190 


2.50 


285 


4,25 


191 


aoo 


8288 


2.50 


192 


ISO 


800 


1.50 


375 


CO4035 2.75 


4.00 


CO4037 2.75 


.50 


CO4040 4 75 


275 


CO4042 275 


BO 


CD4044 2.75 


1.80 


CD4Q49 IJ0 


5 75 


CD4050 1 


.10 


1.10 


CD4115 1,30 



DTL SPECIALS 

3 Dual 4 Gate/Exp 

2 Oval A Buffer 

3 Dual 4 Extender 

it Hex Inverter/ Exp 

5 Hex Inverter 

7 Hex Inverter Gate 
I Dual Buffer 

5 R£ Clocked FF 

6 Quad 2 Gate 

8 RS Clocked FF 

9 Quad 2 Gate 

7 Quad Buffer 

8 Quad Power Gate 

1 Dual 4 Gate/Exp 

2 Triple 3 Gate 

3 Triple 3 Gate 

3 DuaUKFF 

4 DuaUKFF 
7 Dual JK FF 

9 Dual JK FF 



Memorial 

MM 5260 
pi 101 
pi 103* 

7489 

8223 

8225 
74200 
DM8599 

P2102 
2602 



1024 bit RAM (2nd generation 1 1031 5,00 

256 bit RAM 2-00 

1024 bn HAM 7 00 

64 bit RAM 2.75 

25G oil bipolar Field PROM 6.00 

54 bit RAM 375 

Tn State 256 bit RAM 9.25 

Tri-Stet« 64 bit RAM 3.75 

1 024 bit stat ic RAM 1 5.00 

1 02 4 bit St atic RAM 1 6 . 0C 



NOTES; 

a. At Lett! A tested 1 103! Our newly proven program allows ui to 
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b. Occasional I y, *w become backordered in a particular item vtrhire 
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Box 1307 
Colton, CA 92324 
ph #(714) 888 2467 
(ask for FANNIED 



—spec sheets .25s 1 each 

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with order of $ 1 00.00 
—Calif, residents add 6% sales tax 
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TAKE 10(N)% DISCOUNT ON ORDER OF OVER 10 



Nr 









N=l .2,3 



OCTOBER 1974 



49 



THE GDO 



Robert J. Shebal W8ZKL 
306 Potawatomi Blvd. 
Royal Oak MI 49073 



AND 



HE VOM... 




BUT DON'T OVERLOOK 

THE XY 



Every ham is familiar with a few of the 
more common tools of the trade such 
as the VOM and the GDO. But I often 
wonder how many realize what an invaluable 
but often overlooked accessory the XYL can 

Even though she may not have a ticket, 
used properly, she may fill the void in the 
shack and make your operating more 
pleasurable. 

As a for instance, let me relate this lovely 
incident that occurred at this QTH Perhaps 
it will bring a lump to your throat. A 
definition of love and true affection could 
not be more dramatic, and if it brings a tear 
to your eye, it just proves the point. 

It was a typical Wednesday evening with 
the sweet little thing in the living room, eyes 
glued to the Wednesday night movie on the 
mahogany knothole. Meanwhile, back in the 
shack, 1 tuned for some rare DX that was 
coming through on twenty meters. Suddenly 
to my horror the rotor quit on me and 
naturally in a direction away from the DX. 
The beam refused to budge. 

I rushed upstairs and explained my plight 
to the XYL, but she refused to leave the 
movie. Later, during a commercial, she 
agreed to help. Almost the same instant a 
flash of lightning and a clap of thunder 
rattled the house. 

Undaunted, she donned her lineman's 
belt, and at that precise moment — I was so 
proud of her - she began her ascent up the 
four inch pipe mast After all, she weighs 
only one hundred pounds, and the lineman's 
belt with cutters, pliers, hammer, small 
crowbar, 2 5 -foot roll of RG8U and a few 
other things she needed, weighed forty-two 
pounds. 



I watched her as she shinnied up the pipe 
and I could see her quite well during the 
lightning flashes, and between rolls of 
thunder I could hear the rattle of tools as 
they dangled from the belt. 

She yelled at me to turn on the flashlight 
and shine it at the top. She really didn*t 
need the light to find the top, because the 
only way to the top was up. Anyway, she 
knew the way, as she had climbed it many 
times before. Apparently she was not aware 
of the price of flashlight batteries. 

It had begun to rain quite hard, and I 
yelled at her to get a move on up there 
because I was getting wet. She had finally 
reached the top and yelled down for some 
light. I told her the lightning was so frequent 
that she could work during the flashes. 

She got excited and dropped a hammer 
that almost hit me on the head, I told her 
that for being so careless and since I was 
getting wet, I was going into the house and 
dry off. As a nice gesture I watched the end 
of the movie so I could tell her how it ended 
as I was sure she would want to know. 

When she came in the house she refused 
to talk to me just because I had yelled at her 
while she was up on the mast. She wouldn't 
even listen when I tried to tell her that the 
movie ended with John and Marcia getting a 
divorce because John was very mean and 
unreasonable. 

What I originally started out to say is 
simply that the XYL can be a valuable 
addition to the shack, although at times they 
can be a bit difficult. 

Since she is still a bit miffed, please don't 
show her this article. Better yet, I wish this 
would self-destruct after you read it. 

, . W8ZKL 



50 



73 MAGAZINE 



SELECTIVE 



Earl C. Dunn, Jr. W5LCT 

9634 Paula Drive 

Corpus Christi TX 7891 



CALLING 



(remote activation via FM) 



If you are a member of an organization 
_ that operates a busy repeater, chances are 
you monitor the machine only while mobile. 
At home, the nearly constant conversation is 
just too distracti ng. For instance, it inter- 
feres with the great old American pastimes- 
TV watching, not to mention that the 
wife/children/mother-in-law may take excep- 
tion (sometimes violently) to the "noise." 
However, it would be nice to receive those 
calls addressed to you and perhaps special 
bulletins or announcements — hence 
Selective Calling. 

The availability and use of various tone 
pads for autopatch/repeater control provides 
a common encoder on which to design such 
a system. Since tones produced by the 
"pads" are universally common in a stan- 
dardized frequency format, only the decoder 
requires alignment. Assuming your local 
repeater is equipped with autopatch some or 
most of the members will have already 
connected pads in their mobiles. 

The design of a decoding device for use at 
home (or in the mobile) requires consider- 
ation of several factors depending on local 



conditions. First, and most important 
governing consideration, is the number of 
discrete calls (addresses) that will be neces- 
sary to accommodate the amateurs desiring 
personal decoders. This consideration will 
determine the complexity of the decoder 
since the encoder (tone pad) can produce a 
vast number of combinations. Second, con- 
sideration should be non-interference with 
the access code of the autopatch. The third 
objective could be to prevent false activa- 
tions caused by telephone number combin- 
ations. If twelve button pads are in universal 
use and the autopatch does not employ * or 
# for access, then the last two objectives are 
easily accomplished. Actually an access code 
of four numbers that in effect "tests" the 
pad by requiring that all seven of the tones 
be correctly transmitted in order to seize the 
telephone line is a highly desirable situation, 
anyhow. 

Decoding the dual-tone combinations is 
done quite simply using the NE567 (Tone 
Decoder) and the required NOR gates 
(7402). One NE567 is required for each 
tone, so it would be necessary to utilize 









OCTOBER 1974 



51 



seven NE567 if the full pad is to be decoded. 
The decoder presented decodes four of the 
dual tone combinations with four NE567. 

The particular logic to be presented is 
designed to require four digits in proper 
sequence within a defined time period and 
will not accept (for simplicity) two digits 
side by side - such as XXYY, but will 
accept XYXY. The mathematical possibility 
exists for a total of 108 (4.333) combin- 
ations. For example, choose 7, 9, *, and # to 
be decoded and this is one of the four 27 
combination formats. 

7*9# 
7*#9 

7*#* 
7*9* 
7*79 

7*7# 

7*97 
7*#7 
the total combinations 
1) will reveal two which 
are all numerals (7979 and 9797) and these 
can be discarded since they may be part of a 
telephone number. Also, there are two com- 
binations of no numerals (*#*#and #*#*) 
which can be reserved for the use described 
below. Therefore, a repeater group of 104 
can be assigned individual addresses. The no 
numeral combinations can be decoded by all 
or a portion of the members and used — for 
example, as net call, emergency reaction 
group, board of directors net, or any other 
special purpose. This use of these combin- 
ations is important if the system requires 
expansion, A study of Fig. 1 , will reveal that 
simply moving the 852 Hz decoder to 770 



79#* 




7#9* 


79*# 




7#*9 


79#9 




7#*# 


79*9 




7#9# 


797* 




7#79 


797# 




7#7# 


7979 




7#7* 


79*7 




7#97 


79#7 




7#*7 


Development 


of 


the t 


(above and Table 


1) wil 



I 



I 



I209HI 



697 Hz 



7~\ 



770Hz 



±12 



♦ 852 Hz 



-h* 941 Hz 



1356 Hz 



I 



] 



7~S 










— ^ ^ , 



1477Hz 






^1 









97#* 

97*# 

97#7 

97*7 

979* 

979# 

9797 

97*9 

y /Try 

#*79 
#»97 
#•7* 
#•9* 
#*#* 
#*#7 

jj*L-iJU. 

TTW .TJM 
TT 7T» 

#*9# 
#*7# 

*7#9 

*79# 

*7#7 

*797 

*7*7 

*7*# 

*7*9 

*79* 

*7#* 



9#7* 
9#*7 

9#*# 

9#7# 



XfTn^Tr 



9#79 
9#*9 

#79* 
#7*9 
#7*7 
^97 

#7#7 
#7#* 
#79# 
#7*# 

*9#7 

*97# 

*9#9 

*979 

*9*9 

*9*7 

*9*# 

*97* 

*9#* 



9*7# 

9*#7 

9*#* 

9*7* 

9*97 

9*9# 

9*9* 

9*79 

9*#9 

#97* 
#9*7 

#979 

#9#7 
'fjf\ tin 

#97# 

7ml* XT 

*#97 
*#79 

*#9# 
*#7# 

*#*7 

♦ido* 

*#7* 



Fig. 1, Tone pad. 



COMBINATIONS TABLE 

Hz will substitute 4 and 6 for the example 7 
and 9 providing an additional 104 combin- 
ations still "retaining the common no 
numerals (*#*# and #*#*). Moving the 
same decoder up to 697 Hz substitutes 1 and 
2 thus producing another 104 discrete 
addresses. The total capacity is 312 
individual calls which should satisfy most 
requirements. Additional combinations are 
of course possible by adding additional digits 
and by using pure number combinations. 

The digits (decoded dual tones) must 
arrive in proper sequence and the last digit 
must arrive within a time limit (2-3 seconds 
— adjustable) after the conclusion of the 
first one. An initial digit (logic 1 from the 
7402) is applied to the first monostable 
multivibrator (74121). The conclusion of 
the tones causes the M/V to begin timing 
and the Q output goes low (logic 0). This 
frees the first reset-set (R/S) flip flop so that 
digit two causes it to reset {pin 13 goes low). 
Now the third digit will reset the second R/S 
flip flop (pin 4 goes low). With this condi- 
tion the A input of the second M/V is low 
and the receipt of a fourth digit initiates its 
timing cycle. This M/V remains on for about 



52 



73 MAGAZINE 



20-25 seconds while driving the NPN tran- 
sistor to conduct and close the relay. Con- 
tacts of the relay connect the speaker 
allowing reception of the incoming call, A 
portion of the last tones transmitted will 
also be received through the speaker to alert 
the called party. The manual override is then 
activated by the operator for normal opera- 
tion and returned to automatic after the 
conclusion of transmissions. Fig* 2 depicts 
the above described logic arrangement to 
decode any one of the four digit combina- 
tions. As already mentioned, if the fourth 
digit does not arrive before the first multi- 
vibrator automatically clears, then the 
second 74121 cannot begin its timing cycle. 
This delay time can be extended by changing 
the 1 OOfif capacitor to a higher value. 

Fig, 3 is an example of a four tone 
decoder with logic output The intercon- 
necting lines can be translated to a PC board 
layout if the dashed lines are considered to 
be jumpers (or the top face of a double sided 
board). Another construction technique is 
the use of perforated board and "Circuit- 
-Stik" copper strip interconnects and IC 
pads, "MOLEX" socket pins provide 
inexpensive mounting for the ICs. Each 
NE567 decoder uses the same external corrv 



\H I > 



IK 



10 



II 



<4 



A 
B 



74121 



7402 



IN 2 > 



IN 3 > 




JOCWVF 



IIM4 > 



TONE DECODER 



OUTPUT TRANS 



SPKRj 

vc 



AUTO NORMAL 





Fig. 2. A control logic arrangement to decode any 
of the four digit combinations in Table 1 . 




ic 






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ELECTRONICS 



BOX 41 81-H, REDWOOD CITY, CA 94062 
Tel. (415) 851 0455 



OCTOBER 1974 



53 







+ 5 



m 



Fig. 3 m Tone 

ponents and the frequency is determined by 
the setting of the 20K mini-pot. The J juf 
capacitors should be mylar for frequency 
stability of the decoder. The electrolytics 
need only a 10/15V rating. Tune-up consists 
of injecting proper single tone at input 
(many pads will produce a single tone if two 
adjacent buttons are pressed simultaneously) 
and adjusting pot on corresponding NE567 
for a pronounced dip in voltage as measured 
on pin 8, Tone input should be 10O-2OOmV 
and can be obtained easily from the speaker 
side of the output transformer with level 
being adjusted by the 500fi input control It 
is not too critical and the 1N914 diodes 
should protect the ICs from excessive acci- 
dental input levels. The NOR gates (7402) 
combine the outputs of two associated 
decoders to produce a high (logical 1) at the 
indicated output pin. 



decoder. 

Fig, 4 is an interconnect of the logic and 
control transistor which may again be trans- 
lated to a PC board or other layout. A 
typical power supply to provide 5V regu- 
lated for TTL ICs and 12V for relay is 
shown in Fig. 5. Eliminate transformer and 
rectifiers for mobile applications as appro- 
priate. 



IZV 



*\2 



1 



^1 




I AMP 
BRIDGE 




**3 



ICXXVF 
25V 



LM335 MAY BE SUBSTITUTED 
FOR LM309 




iOOpF 



Fig, 4, Control logic, 



Fig. 5* Power supply. 

There are numerous additional possi- 
bilities for this control system. For instance, 
a tape recorder could be incorporated to 
provide a means for "leaving messages" in 
case the called party is not immediately 
available. Relay contacts could start and 
stop a simple tape machine using its remote 
microphone contacts. If an on time of longer 
duration is desired the output M/V can 
trigger an inexpensive NE555 timer which 
can be set for long delays. Also, if your 
group transmits a periodic bulletin, the net 
call can be transmitted prior to announce- 
ments for activation of speakers/recorders. 

■ . . W5LCT 



54 



73 MAGAZINE 



73 STAFF 



REMOVABLE 



VHF/UHF 



MOB 




ANTENNAS 



There may be many reasons why one 
would prefer to have a readily 
removable 2m or other VHF/UHF band 
antenna on one's can Such an antenna 
should, however, be electrically efficient, 
sturdy enough for usage while driving at 
turnpike speeds and yet not require any 
drilling or other marring of the car's surface. 
Some commercial antennas are available 
which partially fulfill these requirements. 
Usually they use a lip type mount and are 
meant to be placed around the trunk area on 
a car. But, there are a number of possibilities 
for the amateur to construct for himself 
sturdy and economical mobile antennas of 
the removable variety. This article describes 
two such possibilities - one in general terms 
and the type which the author found best in 
specific detail The Vi and % X dimensions 
which are given apply to the 2m band but 
these dimensions can be those necessary for 
any VHF or UHF band. 

It may seem at first glance that there 
should not be much involved to building a 
simple l A X antenna which mounts, for 



instance, in a temporary manner on the rain 
gutter of a car. But, as I found out after 
many hours of experimentation, there are a. 
number of precautions which must be fol- 
lowed if a really useful antenna is to be 
constructed. The precautions are not compli- 
cated in nature but this article does con- 
dense many hours of work concerning both 
the mechanical and electrical details of 
constructing a suitable antenna. If followed, 
the guidelines contained in this article will 
result in the construction of an antenna 
providing excellent results on 2m or any 
other VHF/UHF band. 

Where to Mount the Antenna 

The best position to mount a mobile 
antenna is generally the same as for a fixed 
station antenna. Namely, as high and as in 
the clear as possible. In the case of a car, this 
would mean in the center of the roof. A 
removable antenna can be mounted in such a 
position without damaging the car's surface 
by means of a luggage rack holder. A 5/8 A 
base loaded antenna mounted in the middle 






OCTOBER 1974 



55 



of a luggage rack holder with the transmis- 
sion tine coming in by one of the car doors, 
will provide excellent results. But, the in- 
stallation is certainly unsightly and would 
not meet any reasonable definition of a 
readily removable mobile antenna. 

Another possibility is the use of a 5/8 X 
whip held to the car's roof by means of a 
magnetic mount. Such antennas can be very 
efficient but usually the construction of the 
magnetic mount for the home-brewer is both 
too complicated and expensive. This is 
especially true of such a mounting which 
one would want to depend upon as staying 
in place under turnpike speeds or when light 
foliage strikes the antenna itself. 

The other possibilities to provide a secure 
mechanical mount for an antenna while still 
keeping it as high up as possible on the car, 
are either a side window type mount or a 
rain gutter mount Neither such mounting 
position places the antenna in the center of 
the car's roof so there will be some direc- 
tional effects associated with such mounting 
positions. But, the directional effects are still 
less than if the antenna were located still 
lower on the car's body. 

Side Window Mount 

One can form a metal bracket which 
conforms to the dimensions of a side win- 
dow and slips over the top of the window 
much like a giant tie clip. The window can 
still be rolled up fully if the clip fits'snugly 
enough over the top of the window, The 



TOTAL ANTENNA 
LENGTH » METER 



WINDOW 
CLIP 



INSULATORS 




BEND TO AVOtO 
CAR BODY 



Fig. 2, Window mount l A\ antenna. Coaxial line 
shield is NOT grounded at antenna base. 

outside surface of the clip supports the 
antenna mounting terminals (insulated from 
the metal surface of the bracket) and the 
feedline from the base of the antenna passes 
through one of the car doors. But, such an 



antenna must be independent of any ground 
connection to the car. This is not as impos- 
sible as it sounds. Fig. 1 , shows the electrical 
diagram of such an antenna. It consists of a 
Vi X vertical radiator connected directly to a 
520 coaxial transmission line via a 20 pf 
variable capacitor. The shield of the coaxial 
cable at the antenna end need not be 
connected to the car body. The Vi X vertical 
radiator usually has to be bent a bit sideways 
and then vertical in order to clear the rain 
gutter on a car. Once mounted and tuned 
correctly such an antenna will provide very 
good performance. 

Antenna types of this sorts have been 
marketed and used successfully in several 
European countries for a number of years 
for both commercial and amateur radio 
services! The commercial versions mount the 
variable capacitor in a plastic housing (which 
also supports the antenna) on the outside of 
the window clip and the entire assembly 
produces a relatively compact and neat 
appearance. Besides the foregoing, the ad- 
vantages to the antenna are that the variable 
capacitor need only be adjusted for the 
lowest SWR on the transmission line to the 
transmitter. The disadvantages are that the 
electrical performance of the antenna is no 
better than a V* X whip mounted in the same 
position with a ground connection to the 
car's body. Also, the adjustment of the 
variable capacitor will only hold true if the 
antenna is remounted always in the same 
position on the car. If mounted in a differ- 
ent position from that for which it was 
originally tuned (from a front side window 
to a back side window, for instance), the 
different reflecting plane the antenna sees 
will require readjustment of the series ca- 
pacitor for lowest SWR. A somewhat less 
disturbing disadvantage is that the trans- 
mission line for the antenna must be routed 
around one of the car doors and either be 
disconnected at the antenna, or at some 
intermediate point on the transmission line, 
when the antenna is removed from the car's 
window, 

I found that the antenna mounting 
scheme described next was easier to con- 
struct and adjust for a temporary mobile 
situation. However, the Vi X radiator just 
described does have a number of possibilities 



56 



73 MAGAZINE 



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for portable operation which some amateurs 
might wish to develop further. The lack of a 
requirement for a ground connection at the 
antenna end of the antenna transmission line 
makes it particularly attractive for such 
usage and it is a proven commercial design. 

Rain Gutter Mount 

The rain gutter on the side of a car 
provides a convenient mechanical supporting 
point for a temporary mobile antenna. To 
place a Yi X antenna, such as that previously 
described, on a mounting which secures to 
the rain gutter at one point would probably 
place too much mechanical stress on the 
mount This is particularly true for a 2m 
antenna. However, if one can develop a good 
ground connection at the point at which an 
antenna is attached to the rain gutter, the 
antenna mount need only support a Y* X 
antenna. The electrical diagram of such an 



-I/4X ANTENNA 

(21 in. FOR 2 METERS) 




GROUND POINT 
ON DOOR FRAME 



Fig- 2. Electricial diagram of gutter mount ^X 
antenna. 

antenna mounting is shown in Fig, 2, The 
advantage to such a mounting scheme is that 
the antenna needs to be only 14 X long and, 
therefore, can be made to be quite sturdy 
mechanically. Also, since the ground point is 
fixed, the antenna can be removed or placed 
on the rain gutter at the same point as often 
as desired without any effect upon the 
transmission line SWR, There is no series 
capacitor or other tuning reactance needed 
at the base of the antenna and the mechan- 
ical construction of the antenna mount is 
greatly simplified. 

The key to taking advantage of this 
antenna mounting scheme is to find a point 
on the rain gutter of a car to which a 
transmission line can be run and a good 
ground connection made for the shield of 
the coaxial transmission line just before the 
cable reaches the rain gutter. The require- 



ment sounds more difficult than it really is 
in practice. If one examines the moulding 
around the doors on most American cars, 
there will be found to be a number of points 
where one can secure a good ground connec- 
tion and run a coaxial cable inconspicuously 
to a good mounting location for a trans- 
ceiver or power amplifier. Fig. 5, shows how 
I mounted a 14 X antenna on the rain gutter 
(forward passenger side) of a standard 
Pontiac sedan. The coaxial transmission 
cable was brought from a 2m power ampli- 
fier (mounted behind the glove compart- 
ment) underneath the forward side window 
frame moulding (easily removable by two 
screws) to the space between the door and 
the door frame of the car body. There were 
several screws used to secure flashing to the 
door frame of the car body where the 
coaxial cable emerged at the top of the door- 
One screw mounting nearest the top of the 
door was used to ground the shield of the 
coaxial cable via a ground lug after the screw 
and the hole in which it sat were cleaned 
with a file to insure a good metal to metal 
ground connection. These types of screw 
mountings can be found around the door 
frames of any car although the location will 
vary with car makes and models. 

Once the shield of the coaxial cable was 
grounded about a 7,62cm length of the inner 
conductor (with insulation) was left to 
connect to the antenna when it was tem- 
porarily attached to the rain gutter. When 
the antenna was removed from the rain 
gutter, the 7,62cm length of inner conductor 
was just run along the inside upper edge of 
the door frame and remained completely 
inconspicuous. The 7.62cm length of un- 
shielded cable does become part of the 
radiating portion of the antenna but this 
effect is minor on the VHF and lower UHF 
bands. 

Mechanical Details 

A rain gutter mount can either be pur- 
chased or easily homemade. If one can 
obtain spare parts for a car top luggage 
carrier which utilizes a support connection 
to the rain gutter, one need only purchase 
such a single accessory support and turn it 
into an antenna mount The form of such a 
mount is the same as that of the homemade 
support to be described which, in fact, was 



58 



73 MAGAZINE 



copied from a commercial luggage rack 
support. 

The homemade support can be easily 
constructed from hand tools and is made of 
32cm or *48cm thick aluminum stock. It 
consists of two pieces — a T shaped main 
support and a clasp which goes around the 
rain gutter. The dimensions for these two 



-*) f— 3/4 in. 



4 in. 



11 T" piFC£ 
(FRONT VIEW) 



1 



S/4<n 



3ln. 



RAJN GUTTER 
ON CAR 




) 



CLAMP 
PIECE 

(SIDE VIEW) 



BOLT WiTH 
WING NUT 



Fig. 3. Rain gutter mount showing "T piece, 
clamp piece and assembly of two pieces together 
on rain gutter. All holes are W\ 

pieces plus how they assemble together to 
mount on the rain gutter are shown in Fig. 
3. The two pieces are held together and 
tightened to the rain gutter via a bolt passing 
through both pieces and a wing nut This 
arrangement provides a tight mount as well 

4 

as one which is readily removable without 
any tools. The dimensions of the two pieces 
are not important The dimensions suggested 
will provide more than adequate support for 
a 2m antenna but can be made even smaller 
if desired. The T shaped piece can be easily 
cut out of flat aluminum stock with a hand 
saw, The clasp piece is best formed by using 
a hammer and a wooden dowel to form the 
clasp so it fits over the rain gutter of any 
specific car. To prevent marring of the car's 
surface, the lower part of the T shaped piece 
and the clasp should be covered with electri- 
cal tape or a surface covering of epoxy. 

Antenna Placement on Mount 

After having gone through the above 
work, i thought it would be a simple matter 
to mount the vertical antenna radiator 
in-line on the long vertical portion of the T 
piece by means of two insulated power 
supply type screw terminal posts. The inner 
conductor of the coaxial line could then be 
easily connected to the lower one of the two 
insulated screw posts- This scheme was tried 



using teflon insulators on the terminal posts 
and a variety of vertical radiator elements 
ranging from a flat radiator the same size as 
the vertical section of the T section of the 



UPPER HALF OF 
"T" PIECE (FIG.3) 




PL£XJGLAS 

ABOUT 2X2tn SQUARE 

POWER SUPPLY 
BINDING POST 



DOOR FRAME 
GROUND 



Fig. 4. Use of a plexiglass piece to isolate antenna 
from reactive effects of rain gutter mount. 

mount to a thin diameter whip type radia- 
tor. To make a long, painful story short, it 
was not possible to secure less than about a 
2,5 to 1 SWR on the transmission line to the 
antenna no matter how much any vertical 
radiator was shortened or lengthened 
beyond Va A. A reasonable SWR could only 
be secured if some reactance were intro- 
duced between the transmission line and the 
antenna. This clearly indicated that the 
probable capacitive reactance between the 
base of the radiator and the mount was the 
cause of the problem. To test this idea, the 
vertical radiator mounting was offset from 
the rain gutter mount by means of a 
plexiglas separator as shown in Fig. 4. A 
telescoping whip was used as the vertical 
radiator. After a few minutes of experimen- 



I/4X ROD 



PLEXIGLAS 
SPACER (FtG 4) 



RAM GUTTER AROUND 
DOOR FRAME 




Fig. 5- Usage of the mount shown in Fig. 3. on the 
rain gutter of the front right door frame of a car. 



OCTOBER 1974 



59 






\GVTAL 
CONTROL 



OF 







Thotfia* 



s P 



rvTCS 



. Z.HT 










r,i 



Here's the book for every ham who 
wants to design and build a digital 
repeater control system (or who 
wants to just think about doing 
that). Contains sections on repeat- 
ers, basic logic functions, logic cir- 
cuit design, control systems, sup- 
port circuits, mobile installations, 
touchtone, plus a special section on 
a "mini" repeater control system. 
224 pages. 

Hardcover $7,00 Paperback $5.00 



i 

i 



73 Magazine, Peterborough NH 03458 



J Enclosed is $ Please send — Dhard- 

I cover ($7)/Dpaperback ($5) copies of ( 
"Digital Control of Repeaters" to: j 

Name , Call 



i 
i 
i 



j Address 

1 City 

i State _ 



ZIP 



tation, it was apparent that the solution to 
the problem had been found. The length of 
the whip could be adjusted, using a SWR 
meter in the transmission line, to produce a 
perfect 1 to 1 SWR. 

Perhaps the same effect could have been 
obtained by simply separating the vertical 
radiator element from the mounting by a 
greater distance rather than offsetting the 
radiator from the mount But, the former 
appeared far simpler mechanically. 

Fig* 5 f shows how a final version of the 
antenna is mounted on my car. A rather 
large threaded knob rather than a simple 
butterfly nut is used to tighten the gutter 
mount bolt but aside from this, the antenna 
is exactly as described. 

Results and Ideas 

The antenna works almost as fine as a % X 
whip mounted directly in the center of the 
roof of the car, Some directional effects are 
noticeable because of the mounting position 
but for all general purposes they are minor 
unless one is at the absolute fringe area of a 
repeater's coverage. Other considerations in 
a mobile environment once full receiver 
quieting is not achieved usually will over- 
shadow the 1-3dB advantage achieved by 
having the antenna mounted in the center of 
the roof rather than on the side of the roof. 

Checks with a SWR meter showed that as 
long as the radiator element length is left 
unchanged, the antenna could be repeatedly 
mounted on approximately the same posi- 
tion on the rain gutter without effecting the 
SWR. The relatively easy to construct rain 
gutter mount described may be of interest if 
one would like to mount two or more 
vertical radiators on a car and phase them via 
delay lines in the transmission lines to each 
radiator to form an electrically steerable 
radiation pattern. Although perhaps not too 
useful for normal mobile operation, such 
capability would be of definite advantage for 
a mobile station operating over one of the 
Oscar satellites. This mode of operation will 
be described by me in a future article 
concerning simple, electrically steerable an- 
tennas for both mobile and fixed station 
operation over our amateur satellites. 

. , . 73 Staff 



60 



73 MAGAZINE 



George Hinds WB8JYR 
268S3 Maple Dr. 
Westlake OH 441 45 



"TWO-M 




TYPES 
YOU HAVE MET" 



With scanner lights blinking and 
speakers alive with simplex and re- 
peater activity on 2m FM one recent 
evening, I found myself classifying several of 
the amateurs in back of those far away 
voices by their personal operating methods. 
Surely you, too, have met them from time 
to time, for they are not by any means 
peculiar only to my locale. 

For example, just a few minutes ago I 
listened to "Old Joe Toe-Stepper." Verily, 
Joe has "the fastest thumb in the midwest!" 
Never yet has he allowed a second of silence 
to elapse between transmissions when in 
QSO; no "breaker" is going to get in on Joe 
at any cost (even- though it may be an 
emergency involving life and limb). 

And here is "Billy the Breaker" again! 
Just when an interesting QSO is underway 
and listening is both enjoyable and informa- 
tive, Billy "breaks." More often than not, he 
succeeds in breaking one's train of thought, 
the interest of the listening stations and 
finally the QSO, since his contribution is 
limited to "AhV 1 "OhY* "I don't know" 
and "Am [ getting out?" 

Everyone on the local repeater has met 
"Carl nock watcher" and caught him in his 
first contact with someone new on the 
repeater. Someone told Carl that the 
machine has a three-minute timer to limit 
emissions and, by golly, Carl wants his share 
of that air time. With fixed stare at the clock 
on the wall of his shack, he mumbles into 
the microphone for two minutes and fifty- 
nine seconds with each transmission, despite 
the fact he has nothing really to say. 
However, I have noticed lately that Carl is 
more and more often calling on the repeater 



without raising a response; even the newest 
newcomers soon learn to avoid that boring 
trap from which it is so difficult to escape 
gracefully, 

A few nights ago I listened to "Sid 
Screamer." You know Sid — he's the fellow 
who believes unshakabiy that yelling into the 
mike will carry his signal louder and clearer 
than anyone else on the machine (even 
though his excessive deviation just took him 
out of the repeater receiver). Oh, you know 

Sid? 

Does everyone have a ham in the area like 
"Henry the Hardheard?" You can often hear 
him complaining at hamfests about his al- 
ways brilliant QSCTs being clobbered by 
some nasty repeater that is deliberately "out 
to get him," 1 heard him this summer crying 
that all too often the local repeater would be 
activated deliberately to interfere with a 
QSO of his. The truth of the issue was found 
to be that old Hank insisted on working 
simplex on the repeater output frequency 
right under the umbrella of the machine and 
the "interfering" stations were mobiles away 
out in the far reaches who could not know 
of the QSO going on. No, Hank insists he'll 
continue to use "simple" 94 (or 88 or 16 
too) for he won't be regimented away from 
his pet simplex frequency by any repeater 
council plans. 

All too numerous among the ranks of 
hamdom is "Pete Plunker." Pete's two-meter 
operation consists of switching his rig from 
repeater to repeater and plunking each one 
successively and repeatedly to reassure him- 
self that all the area machines are operation- 
al. Of course devotion to this self-imposed 
duty requires that he perform his plunking 



OCTOBER 1974 



61 



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6N2. Aerotron 500, HA 460. TX 62 ur VHF 1) 



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Communicator. Just 
plug into mike jack 
and crystal socket. 

Compact self-contained 
modulator measures 
4"x 3" kVA'\ 



• Works with Communicator 1, 11, 111, IV 

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secretively and with a high degree of regu- 
larity so as to elicit yelps of frustration and 
despair from the monitor stations on the 
frequency. No, Pete obviously doesn't 
identify himself nor pay dues to any of the 
repeater groups. He rationalizes his activity 
by saying that he doesn't use repeaters (he 
just tests them!). However, he does spur the 
technicians responsible for the machine to 
greater activity; at last report they were 
working on a guard system for the repeater 
to curtail Pete's perverted enjoyment of 
two-meter FM (and sorrowfully thus deprive 
some transient mobiles from having a repeat* 
er available). 

And then there's the sorriest specimen of 
all, the local "Mystery Ham" who has 
obtained the access touch-tone code for the 
various repeater phone patches and spends 
his days and nights indiscriminately opening 
phone patches without identifying or even 
dialing up a number. He just lets the patch 
hang until the timer takes it out or a 
monitoring station shuts it down! There are 
some who say it can't be a ham doing this 
but instead is someone of questionable (and 
unprintable) ancestry who delights in des- 
troying the good work of others. Whatever 
or whomever it is, dire threats of "reverse- 
type** antenna parties (or worse) are directed 
toward him and direction-finding is the 
project in many minds. 

Despite these few drawbacks, 2m FM is 
now becoming the fastest-growing segment 

of amateur radio* The specimens identified 
above are vastly outnumbered by good 
amateurs who make the band a really fine 
place to hang out. Countless stations are on 
frequency, not just for local ragchewing, but 
to offer a friendly voice and helpful direc- 
tions to all who pass through our area. One 
has but to complete a lengthy trip with the 
companionship of a good 2 meter rig to 
notice the miles of boredom have been 
turned into smiles of friendship. On free- 
ways or through barren back roads, a con- 
tact with a fellow ham is generally available, 
so the day (or night) is made shorter and 
^highway hypnosis" is dispelled. Try it. 
Thousands of fellow hams know you'll like 
it! 

- . WB8JYR 



62 



73 MAGAZINE 



RADIO LIFE-INSURANCE 

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Model SR-C826 MA j 

Repeater RPT-1 $59.00 total 

Our exclusive Astropoint Radio 
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the flat rate repair charge listed 
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OCTOBER 1974 



63 



Pete Walton VE3FEZ 

421 Lodor Street 
Ancaster, Ontario 
Canada 



HOW 



OWIN 



RENDS 





NC 



AND 

THE 2-M MAN 



v. 



The other night I walked into the club 
shack, and there it was, a new rig. It 

was about 1 2 inches long, 8 inches deep and 
about 4 inches high. On the front were two 
rows of eight lights and eighteen 
pushbuttons. It also had an on and off 
switch, volume control and squelch. Hmm, 
looks like two meter FM with automatic 
scanning, I should explain that I am a 20m 
phone man and never used FM gear before* 
Maybe I should see what this FM business is 
all about. 

Power on. That was easy. One of the 
sixteen lights even came on, the first one in 
the top row. That must mean that we are on 
the first channel. Nothing to this FM busi- 
ness. Wonder why it won't scan? Push all the 
buttons in — still won't scan. Pull all the 
buttons out again — still no scan. This looks 
like a problem. Try all the buttons one at a 
time; still no luck. Now there is only one 
control that I have not moved. Advance the 
squelch control to get rid of that awful 
noise. Ah ha! It starts to scan all eight lights. 
Seems that this scanning feature locks up 
even on noise; good idea. Looks just like 
Christmas now, scanning all eight lights over 
and over again. Still haven't heard anybody 
yet, Let's try a CQ and see if it works. 
Pushed the channel one transmit button and 
the rig stopped scanning with the channel 
one transmit light on. This all seems very 
normal, even to a twenty meter phone man. 

Well, here goes. CQ. C.Q. CQ. CQ. Two 
meters. Got an answer right away. I was told 
in no uncertain terms that you don't call 
C.Q, on two meter FM especially through a 



repeater. Okay, I explained that I was new 
on two meters and didn't know all these 
things yet. The fellow was really very nice 
about it and explained all sorts of things 
about FM. 

Then he said, "Let's go to 94," Oh, oh* 
no 94 on this rig, only 1 to, 8, but he 
explained this also. Pushed in channel 4 and 
sure enough there he was. We had a really 
enjoyable QSO on 94 - no QRM, no QSB, 
and it was very informative . 

He did, however, forget to remind me of 
one very important little matter which I will 
discuss next. After we signed off, the rig 
started scanning again. It stopped scanning 
on channel 3 and somebody asked if there 
was anyone on frequency. I answered and 
explained that this was only my second QSO 
on two meters. The fellow was very nice and 
volunteered all kinds of information about 
two meter operation. I told Mm all about 
the fun I was having on two meters and then 
went on to completely describe our club 
station. Told him about my own station, I 
then made some comments about how much 
better the lower bands were, "Okay, back to 
you, old man," . . . hmmm, nobody there! 
Now I began to remember what the other 
fellow had forgotten to remind me about. It 
seems these repeater stations have some type 
of time-out device. Forgot about that ... I 
listened to the other channels for a minute 
and heard a fellow say he was on his way out 
to the repeater and he was suggesting the 
possibility that I may be of doubtful parent- 
age. Oh well, back to twenty meters. I can 
stay out of trouble down there. 

. . . VE3FEZ 



64 



73 MAGAZINE 



Complete 

MOTOROLA 
Plus I 



Cecil Phelps K4HHI 
P.O. Box 154 
Delco NC 28436 




NG 



If you need complete metering, monitor- 
ing, and control for alignment or routine 
service of Motorola FM units, this article 
should be of interest. This unit is fairly 
simple to build, has all the metering available 
in the popular Motorola P8501 Test Set, and 
new parts cost should run under $30.00, 
much less with an average goodie box. 

In addition to the 8 position transmitter 
and receiver monitoring, it has the follow- 
ing: I field strength meter with gain control; 
2 speaker and volume control; 3 four pin 
mike jack; 4 PTT hold switch; 5 3V dc jack 
(GE Progress Line etc); 6 tone input jack. 

Parts layout is not critical, so each indivi- 
dual can come up with whatever suits him 
best. Most parts are stocked at local supply 
houses, balance available through any of the 
popular mail order catalogs. Mine was built 
on a ST x 7" x 2" chassis. 

When the wiring is completed, the usual 
visual checks should be made for loose 
solder, cold joints, wires or pins shorted, etc. 

OPERATION 

Note: field strength, plate current, and 3 
VDC switches stay in the normal-off posi- 
tion, unless in use. The transmitter-receiver 
switch should be placed in correct position 
before plugging into respective unit. 
Field Strength — use small antenna or test 
load for rf pickup. Key transmitter and 
adjust sensitivity. 



Polarity - change position any time meter 

reads backwards. 

3 volts dc — ,use for GE Progress Line, TPL, 

etc. 

Plate Check Only — meters plate current in 
P. A. regardless of 8 position switch. 
Transmitter Key — holds transmitter on for 
alignment, etc. 

Mike Jack — for using mike in trunk, etc. 
Tone-In Jack — for inserting audio for adjus- 
ting modulation. 



Position # 


Average 


Receiver 






Reading 




1- 




-1.5 


2nd if G 1 


2- 




-18/40 


1st LIM Gl 


3- 




-25/35 


2nd LIM G 1 


4- 




Zero 


Disc. Secondary 


5- 




-12/16 


Disc. Primary 


6- 




-12/40 


Osc. Gl 


7- 




+10 


B+ 200V 


O" 




+10/20 


Audio Out 




Average 




Transmitter 




Reading 






1- 


None 




Blank 


2- 


None 




Blank 


3- 


-13 




Tripler Gl 


4- 


-10 




2nd Doubler G 1 


5- 


-16 




Dou-Driver G 1 


6- 


-15 




PAG I 


7- 


+ 17 )HV= 


reading x 20) 


B++ 340 V 


8- 


+ 40 (A V= 


1 5 V FS) 


A+ un keyed 



Table 1. Average readings for 80 D series, trans- 
mitter and receiver. 



OCTOBER 1974 



65 




GATEWAY 

ELECTRONICS 

8123 25 PAGE BOULEVARD 
ST. LOUIS, MISSOURI 63130 

<314> 427 6116 



THUMBWHEEL SWITCHES 

STANDARD SIZE - 0.5 x 2.125 x t.78 
10 position decimal S3. 00 

10 position BCD & compl,$4.00 
End Plates (per pair) $1.45 

MINIATURE SIZE - 0.312 x 1.3 x 1.3 

10 position decimal $2.50 
1 pos. BCD & comp, $4,00 
10 pos. BCD only $2.75 

End Plates (per pair) $1 .00 
Divider Plates $1 .25 

Blank Body $ .30 



K 



\l 



^^ 




n< 



|8 : 



i\ 



All switches are black with white fig- 
ures and snap-in front mounting. 



TRIAC CONTROLLER - Triac ad- 
justable light dimmer rated at 1200 
watts — 0-1 15 volt. Ship . wt. 2 lbs. 

$3.50 

2" SCOPE TUBE SHIELD - Manf. by 
Millen. Ship.wt. 1 lb. $3.95 

PAMONA BOX- 2 1/4x1 1/8x7/8 
Miniature box w/BNC plug & jack - 
good for attenuators & other small 
projects. Ship. wt. 1/2 lb. $3.95 

BNC JACK TO »NC PLUG 




NIATURE SWITCHES - DPDT 
Miniature Push-button switch $1.50 

MINIATURE SWITCHES - SP6T En- 
closed Miniature rotary SW. %" dia. 

$1.50 

EQUIPMENT COOLING FAN- 115V 
AC - 3" diameter - w/mounting 
bracket -3 lbs. $3.50 

S5 Mttumuni Order VfStt u& when tn St Louis 
Please include sufficient oosiage. 



3V OC 
NORMAL 





NORMAL> PA IP 

9 ONLY 






2.5 mH 



/ 



FS 

ANTENNA 





J I RN PLUG 
« < t 



< 2 



LJ, 



<3 



<4 



<- 



<5 



06 r-*< 

20 MEG m tt 



<6 



<T 




NORMAL 



FOR MOTRAC, 
USE ADAPTER 
PLUG fit PIN 

TO 14 PIN - 
rf* 10 GOES TO 
* 14). 



Fig. 2. For Motrac, use adapter plug (11 pin to 14 

pin - #10 goes to #14). 

8 Position Switch — for transmitter and re- 
ceiver stages. See Table 1 for 80D series. 
(Most are alike, but consult manual for exact 
specs). 

PARTS LIST 
Meter - 50 juA (2500U) 
1 1 pin plug — Amphenol 86GPI 1 
4 pin jack —Amphenol PC4F 
Switch (9 pos,) - 9 position rotary, I pole 
Switch (Xmtr-Rcvr) - 2 position rotary, 3 
pole.. 

- . -K4HHI 



66 



73 MAGAZINE 



Frank J. Milter K6QFO 

R.A.C.ES. Club 

Country Government Center 

Redwood City CA 94063 



AM Or FM 



INPUTS 



(on the same frequency) 



Most modern repeaters have gone to 
FM input and FM output. Of the few 
AM repeaters left in existence most are 
connected with Civil Defense or RACES 
groups. Just try and get the cities and 
counties to buy new or used FM equipment 
all at one time when they still have good 
operating equipment. It's impossible. 

An AM input to FM output machine was 
put into service in San Mateo County to 
connect the coast to the main peninsula. 
There is a range of mountains running the 
length of San Mateo County and almost 
down the center. Using simplex AM units, 
communications were almost impossible 
from the coast to the peninsula. With the 
repeater, solid communication to and from 
the coast was possible. 

In the beginning most of the stations 
were AM into the repeater, As the Civil 
Defense group got used to the machine more 
and more wanted to try FM, Try putting an 
FM signal through an AM receiver. The first 
plan was to use another input frequency, but 
due to the limited Civil Defense approved 
frequencies the same input had to be used 
for AM and FM. 

Upon experimenting it was found that an 



FM and AM receiver could be tied together 
with an antenna splitter (with preamp built 
in) and worked like a dream. The preamp 
was used to cut down the losses when 
connecting the two receivers together. Audio 
output from both receivers is tied together 
through small solid state amps. The keying 
of the repeaters with an FM receiver usually 
used a carrier operated relay (COR), which 
worked fine on an FM signal, but when an 
AM station came on the COR chattered or 
refused to work. Finally a voice operated 
relay (VOR) was used on the composite 
audio and worked fine. 

We now have quite a growing group using 
anything from Twoers to Motorola bricks, 
this really brings out the old equipment and 
an incentive to go on FM. Some day we will 
remove the AM receiver, but during a disas- 
ter every piece of equipment can be used on 
the AM or FM input. Try it, it really works. 

. . .K6QFO 

K6QF0 is located on Pise Mountain in 
the coastal range at an elevation of 2000 
feet Covers Bay area, and parts of the 
Sacremento Valley, Coverage drops off in 
San Jose. 



OCTOBER 1974 



67 



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68 



73 MAGAZINE 



Allan J. Mac Donald WA1KJI 
31 Warwick Avenue 
Williams to vm MA 01267 




HER 






AT 
WATERPIPE 



ANTENNAS 
FOR TWO ME 




FM 



the Northern 

Club (K1FFK 

146.10-70) 

6 of these in 



There have been numerous articles writ- 
ten on this subject in the past; yet the 
fact that confusion abounds is confirmed by 
talking to groups who have tried to build 
these devices. 

At the present time 
Berkshire Amateur Radio 
1 46.3 I -91 ) {WA1KFZ 
(K1FFK 52.76-52.66) has 
operation - three 20 footers, two 30 
footers, and one 40 footer. These antennas 
have proven themselves perfect for amateur 
repeater use. 

The ideas presented here were developed 
by K2CBA, K1DEU, and myself while con- 
structing and checking out the club's anten- 
nas. 

The antenna is a multiple of 1/2 wave 
elements with 1/4 wave sections on each end 
and a 1/4 wave conductor which acts as a 
stub to reduce feedline radiation. See Fig. 1. 

Construction of the antenna proceeds as 
follows: 

1. From the formula X/2 = 492/F(Hz) 
calculate the half wave length in air for 
146.00. This comes out to 3.4 FT or 40.8 
inches. 

2. Select the coax you wish to use and 
obtain information on the velocity factor of 



the coax. Generally solid dielectric coax has 
a velocity factor of approximately .66 while 
foam dielectric velocity factor is approxi- 
mately + 8, I would recommend the solid 
because of its better heat resistant qualities 
and it makes a smaller antenna. For solid 
coax 1/2 wavelength is approximately 26.90 
inches. In general, the velocity factor varies 
by as much as 75% from manufacturer to 
manufacturer. Measurements with a pulse 
generator and Tektroniks 585 confirmed 
that there was enough variation that some 
sort of procedure for taking this into ac- 
count must be developed. 

3. To proceed with the fabrication, two 
pieces - of equipment are needed —a signal 
generator (low power transmitter) covering 
the range desired (140—150 MHz) and an 
SWR bridge. With these in hand, fabricate a 
3 element section (three 1/2 wave elements 
including the 1/4 wave top element (13,5'*) 
and radiator 19.25" and the bottom 1/4 
wave stub. With this completed, hang the 
antenna equidistant from the floor and 
ceiling and measure the resonant frequency, 
If this is not within 7I Hz of your desired 
frequency open the antenna and trim the 
1/2 wave elements until you are within that 



OCTOBER 1974 



69 



DATA 
SIGNAL 

the latest in station accessories 

AUDIO AUTOMATIC GAIN 
CONTROL AMPLIFIER 

Is your tone decoder having problems due to in- 
put signal variations? If so, eliminate these and 
other problems caused by weak, strong or vary- 
ing input signals. The AAGOl will take signal 
levels between 50 mV to 5 Volts and feed a 
clean rock stable signal to any decoder for per- 
fect operation. Give your decoder a chance to 
decode properly with our AAGC-1 amplifier. 

Shipping Weight 3 oz. $14.95 kit 

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20 dB 


2.5 dB 


$15.50 


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2 meter 


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40 dB 


2.5 dB 


$30.50 


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220 MHz 


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17 dB 


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220 MHz 


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35 dB 


2.5 dS 


$30.50 


$36.50 



CRICKET 1 ELECTRONIC KEYER 

A popularly-priced IC keyer with more features 
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OTHER EXCITING PRODUCTS INCLUDE 

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range. Do not worry about the actual 
VSWR; look only for the VSWR minimum. 
4. Depending on whether you are slightly 
high or low compared to your design fre- 
quency, alter another pair of 1/2 wave 
elements cutting them 1/4 — 1/2" longer if 
you are too high and 1/4— 1/2 " shorter if 
you are too low. Solder these into the 
antenna and check again. Continue this 
operation adding pairs of elements and 
checking until you have reached the 
mechanical length you desire. The antenna 
can be any length you feel is mechanically 
supportable. If possible , try to stay a little 
on the high side of your design frequency. 



m 



SOLID CONDUCTOR 
1/4 A IN AIR 



SHORTED RG-6U COAX 
i/4 A IN COAX 




"n" ELEMENTS 
\/2 A 1N COAX 



SOLDER 



1/4 A JN COAX 




SOLID CONDUCTOR 
1/4 A IN Alfi 



Fig. I. Antenna construction. 



70 



73 MAGAZINE 



r 



How to win the fist fight... 
with CW equipment from HAL. 




The economical HAL 1550 keyer. 

The easy-to-use 1 550 keyer is your answer if 
you're looking for an electronic keyer that lets 
you send accurate CW effortlessly. Send 
from 8 to 60 WPM with conventional, iambic, 
and dot memory operation. Operates with dual 
or single lever keys. The optional 15507 ID 
automatically sends Xi DE M followed by your 
station call. For fast accurate CW, order the 
HAL 1 550/ ID or 1 550 today. 

Price: 1550/ ID, $95; 1550, $75; ppd USA. 
Air shipment, add $3, 



ID-1 A repeater identifier. 
Commercial quality, low price. 

The HAL ID-1 A brings the radio amateur a 
commercial-quality repeater identifier that 
complies with FCC ID requirements. It has a 
unique read-only-memory that you can easily 
reprogram yourself. Capacity of the ROM is 
39 dots, dashes and spaces. TTL IC's assure 
immunity from noise and temperature. ID inter 
vals available: 3, 6, 12 or 24 min. Specify call. 

Price: $115, ppd USA. Air shipment, $3. 













Send perfect CW every time 
with the MKB-1. 

A complete Morse keyboard. Code speed 
variable from 10-60 WPM with variable dot-to- 
space ratio (weight). All solid-state, featuring 
computer-grade components. Complete alpha- 
numeric and punctuation keys, plus an optional 
"DE-call sign" key factory programmed for you. 
Includes built-in speaker/ oscillator monitor. 

Price: $290 Assembled, $199 Kit, ppd USA. 
Without ID, $250 Assembled, $170 Kit 
Air shipment, $5. 



CW— and RTTYon one keyboard! 
The HAL DKB-2010. 

All solid-state. Type out CW at 8-60 WPM. Ad- 
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Five standard two-character keys, 2 shift keys, 
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buffer Optional 64 or 128 key buffer also 
available. 

Price: $425 Assembled, $325 Kit, ppd USA. 
64 key buffer $1 00, 1 28 key buffer $1 50. 
Air shipment, $10, 



HJ 



HAL Communications Corp, 
Box 365, Urbana, Illinois 61801 
Telephone: (217) 359-7373 



I 

Name 
I 



Enclosed Is $ for: D DKB-2010 □ MKB-1 □ 1550 □ ID-1 A 

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OCTOBER 1974 



71 



5. When you have reached your desired 
length, stop adding sections and run a test 
by powering the antenna from a transmitter 
and running a wave meter (absorption) up 
and down it, each element should be radi- 
ating equally if you have no shorts or opens. 

6. Now tape each junction completely 
with 3-4 layers of good electrical tape. This 
gives mechanical integrity and some sealing 
to the connection. 

7. Again check for the minimum VSWR 
point. Hopefully you have come out a little 
(250-500 kHz) high of your design frequen- 
cy. With the antenna draped in the air again, 
take some 1" wide strips of aluminum foil 
and hang over the taped electrical connec- 
tions. Play with these strips, removing, ad- 
ding, etc, until the minimum VSWR point is 
exactly on design frequency and the VSWR 
is also minimum, It is a two-man job at this 
point. 

8. When you have the thing "right on," 
tape over the foil permanently holding it in 
place. 

9. If you have built a 25-40 footer, your 
VSWR should come out to better than 1.1 



1) Cut to desired length + 2*0 



ft 



E 






R6/8U Solid Dielectric 



2) Cut insulation back V* each end flux and tin 
each end. 



TIH 




TIM 




3 J Using tubing cutter, cut shield off 3/4" from 
first end f measure final dimension (from calcula- 
tions) from shield on cut end to other end t mark, 
and cut shield with tubing cutter. 



CALCULATED LENGTH 




4) Using single edge razor trim insulation leaving 
III 6—1 18 ' ' remaining. 








Fig. 3. VSWR plots on 2 antennas. 



to 1 and hopefully 1,0 to 1. If you have 
built an antenna less than 25 feet, your 
VSWR may be as great as 2.0 to 1 . This is 
because the impedance of the bottom 1/4 
wave element is not correct (I think). This 
can be compensated for by the addition of a 
matching stub (solid conductor) in parallel 
with the feed line quarter wave stub. Vary 
the point of soldering this to the feed line 
for minimum VSWR - using this technique, 
the VSWR can be brought under 1.2 to L 



1/4 A 
CONDUCTOR 



FEED 
LINE 




FIRST t/4 A 
SECTION 



MATCHING 
STUB 



Fig, 2. Method of element preparation. 



Fig. 4. 

10. Now pick up some Mi 2" OD PVC 
pipe and fittings and build a housing for 
your new creation. The 20 foot unit should 
show six dB gain while the 40 foot should 
have 9 dB gain omnidirectional, of course. 
The longer antenna will have a flatter pan- 
cake coverage pattern (vertical plane); and, 
of course, its VSWR plot will be sharper. 

Good luck! Hope this has helped. 

. . .WA1KJI 



73 MAGAZINE 




Tempo's VHF transceivers offer 
commercial performance at amateur prices. 
Compare these transceivers with any other 
available. Compare their performance, their 
quality of construction, their ease of 
maintenance, and then compare prices. Your 
choice will have to he Tempo. 







TEMPO Jmh 



So much for so little! 2 watt VHF/FM 
hand held. 6 Channel capability, solid 
state, 12 VDC, 144-148 MHz (any two 
MHz), includes 1 pair of crystals, 
built-in charging terminals for ni-cad 
cells, S-meter, battery level meter, 
telescoping whip antenna, internal 
speaker & microphone, $199.00 



TEMPO CL MS 

The CL-146 offers operation on the 146 MHz amateur band. The 
price includes a microphone power cord, mounting bracket and 
one pair of crystals, A full line of accessories is also available. 

• 12 channel capability * 13 watts or a power savings 3 watts 

• All solid state, 12 VDC • 144 to 148 MHz (any two MHz with- 
out retuning) * Supplied with one pair of crystals • RF output 
meter, S-meter, receiver detector meter • Provisions for exter- 
nal oscillator • Monitor feature • Audio output at front panel 
•Internal speaker • The Price: $299.00 




TEMPO I CL 220 




TEMPO 

VHF/UHF Power Amplifiers 
Solid state power amplifiers for use in 
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VHF (135 to 175 MHz) 






As new as tomorrow! The superb CL-220 embodies the same 
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At $299.00 it is undoubtedly the best value available today. 



rive Po 


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Model No. 


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2W 


130W 


1 30 A02 


$199 


10W 


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130A10 


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30 W 


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$189 


2W 


SOW 


80A02 


$169 


10W 


sow 


80A10 


SI 49 


30W 


BOW 


80 A 30 


SI 59 




UHF (400 


to 512 MHz) 


2W 


70W 


70D02 


S270 


10W 


70W 


70D10 


$250 


30W 


70W 


70D30 


S210 


2W 


40W 


40D02 


S180 


10W 


40W 


40D10 


S145 


2W 


row 


10 DO 2 


S125 



FCC Type accepted models also available. Please write. 



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Butler, Missouri 64730 816/679-3127 



AVAILABLE AT SELECT DEALERS THROUGHOUT THE U.S. 



Puces subtett to tfcaAge without notice 



MOTOROLA MODEL NUMBERS 



More and more hams are enjoying 2 
meter FM and many are using or thinking of 
using low priced Motorola used equipment. 



The following info may help clarify the 
meaning of the model nomenclature. 



T43CMT-1130A 



1st character (T) (Housing) 
B = Base 



D 


= Dash mount 


H 


= Portable (max. portabil 


M 


= Monitor rec. 


P 


= Portable 


R 


= Railroad 


T 


- Trunk mount 


U 


= Universal Mount 


2nd character (4) (RF out) 





= Rec. only 


1 


= less than .75W 


2 


= .75- 3.9W 


3 


- 4 - 1 5W 


4 


= 16-40W 


5 


= 41 -69W 


5 


= 70- 100W 


7 


= 101 - 134W 


3rd character (3) (Freq.) 





= Below 25 MHz 


I 


= 25-54 MHz 


2 


= 72-76 MHz 


3 


= ]44_ 174 MHz 


4 


= 450 - 470 MHz 


4th character (C) (Rec) 


A 


= Sensicon "A" 


B 


= Unified chassis (450 M) 


C 


= Mocom 


D 


= Portable 


G 


= Sensicon"G" 


H 


= Motrac 


L 


= Motran 



In the example at the top of the page, 
T43CMT-I130, this would be a trunk 
mount, power between 16 & 40 watts, 
between 144 & 174 MHz, Mocom receiver, 
Dispatcher transmitter, fully transistorized 



5th character (M) (Xmtr) 

A = 30-60W "A" transmitter 

B = Unified chassis (450) 

C = Lo + UHF portable 

E = High band portable 

G = Mobile +AC utility "G" xmtr 

H - Motrac 

L = Motran 

M = Dispatcher 

6th character (T) (Power) 

B =117V.AC 

C = Battery (dry) 

D = Dynomotor 

M = Transistorizes w/ int. bat 

N s No power supply 

T = Fully transistorized 

V = Vibrator 

7th character ( 1 ) (Squelch) 
1 = Carrier 
3 « Dual (PL) 

8th character (1) (Chan. Sp) 

= Wide band 

1 = Split channel 

9th character (3) (#of freqs) 
= I trans & rec 

3 =2 trans & rec 
7 =3 trans & rec 

10th character (0) (Power) 

=12 volts 

1 =6/12 volts 

4 =6 volts 

power supply, carrier squelch, narrow (split) 
band, 2 freq using 12 volts. This may help 
those who are new at the game of trying to 
figure out what a mobile unit really is. 

Reprinted from SCOPE 



74 



73 MAGAZINE 



Ward Stewart VE3FGS 

8 Church Street 

Penetanguishene, Ontario 
Canada 



ADJUS 



NG FM DEVIATION 



Proper adjustment of the deviation con- 
trol is important for good FM com- 
munications- If it's too low, the audio at the 
receiver is also low. If it's too high, you may 
be over-deviating and getting signal reports 
that — though your signal is strong — break 
up when you talk. 

Test instruments for measuring transmit- 
ter deviation cost upwards of $250. There is, 
however, a shortcut method of deviation 
measurement using an FM receiver and an ac 
voltmeter (or oscilloscope). 

To adjust deviation using this method, 
you must use a receiver of the appropriate 
bandwidth- Economy price monitor receiv- 
ers of undetermined bandwidth are of no 
use here. 

If you want to use a narrow band ±5 kHz 
system, you must use a receiver with ±5 kHz 
bandwidth- If your system contains both 
wide and narrow band units, adjust all 
transmitters for narrow band operation. This 
will cause slightly reduced audio in the wide 
band receivers, but will provide much better 
overall performance. Most commercial units: 
Motorola, GE, etc., have power supplies 
which will allow the transmitter and receiver 
to be used simultaneously for short periods 
of time. Refer to the schematic for your 
particular rig to see how this can be accom- 
plished, as you can then check your trans- 
mitter deviation using the associated receiver 
as a monitor. 



The hookup for measuring is as follows: 
Connect an ac voltmeter or scope across the 
speaker terminals. Apply a 1 kHz tone to the 
transmitter. If an audio oscillator is not 
available a constant whistle of about the 
same frequency into the mike will do. With 
the deviation control at the lowest position 
(CCW) key the transmitter and slowly ad- 
vance the control while watching the ac 
meter. If feedback occurs, or if you can't 
stand the noise, substitute a 5W resistor of 
the right value for the speaker. 

As you increase the transmitter deviation 
you'll see a fairly linear increase in the 
receiver audio level, followed by a flattening 
out, and then, as you go outside the pass- 
band of the receiver, the audio level will fall 
off and the noise level will increase. This is 
an excellent example of what happens when 
an over-deviated signal is received by another 
FM mobile. 

Repeat the control adjustment several 
times, paying particular attention to the 
point at which the linear rise just starts to 
flatten. This is the point at which the 
deviation control is properly set, 

I've used this method to set deviation on 
many, many occasions and have been 
amazed at its accuracy when compared 
against properly calibrated instruments. 

. - .VE3FGS 






OCTOBER 1974 



75 



OCTOBER 



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Hi -performance VofL Comp. 
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A 6 C - Squelch Amp. 
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Dual Peripheral Driver 

Dual Peripheral Driver (75453) 

2 Watt Audio Power Amp 

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LM 75451 Dual Peripheral Driver 

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MAN 4 type Seven Segment Dip - S2 25 ea 3 o* mt>reS2 OOea 



TTL 



7400 


$ 23 


7453 


S 27 


74157 ; 


S1.55 


imu; 
CD4001 


> 
S 60 


7401 


23 


7454 


40 


74)60 


1.65 


CD4002 


60 


7402 


23 


7459 


25 


74161 


1 65 


CD40O9 


1 40 


7403 


.23 


7460 


.25 


74t63 


2.50 


C04010 


.60 


7404 


25 


7470 


45 


74164 


2.50 


CO401I 


60 


7405 


24 


7472 


41 


74165 


250 


CO4012 


.60 


7406 


50 


7473 


47 


74166 


1 75 


CD4013 


1 50 


740? 


50 


7474 


47 


74170 


3.00 


CD4016 


1 40 


7408 


.25 


7475 


90 


74173 


1.75 


CD4Q23 


60 


7409 


.25 


7476 


47 


74174 


1.85 


CD4025 


.60 


7410 


23 


7480 


.50 


74175 


1.85 


CD4027 


1 25 


7411 


30 


7482 


1 75 


74176 


.85 


CD4030 


.60 


7413 


89 


7483 


1.15 


74177 


85 


74CO0 


66 


7416 


45 


7406 


MO 


74160 


1.05 


74C04 


70 


7417 


4$ 


7486 


.47 


74181 


3.75 


74C20 


65 


7418 


25 


7488 


4.00 


74182 


1,00 


74C173 


2.60 


7420 


.23 


7489 


3.00 


74184 


2.30 






7421 


.27 


7490 


.89 


74185 


2.30 


B0O0 Series 


7423 


32 


7491 


1J5 


74187 


7.00 


8090 


S .35 


7425 


.27 


7492 


.95 


74190 


1.50 


8091 


.55 


7426 


31 


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74191 


1.50 


8092 


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7427 


32 


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t.50 


8093 


55 


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,40 


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74193 


1 50 


8094 


55 


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33 


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1.25 


8097 


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74197 


1.05 


8098 


55 


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74198 


2.25 


8121 


90 


7440 


23 


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1.05 


74199 


2.75 


8123 


1.60 


7441 


1 10 


74125 


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74200 


7.00 


8130 


2.25 


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1.05 


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.80 






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2.70 


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1,10 


74141 


1.15 


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3.25 


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115 
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75 


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125 


74153 


1,50 


74S Se* 


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8288 


.90 


7448 


1.25 


74154 


1.25 


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8336 


,60 


7450 


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74155 


L30 


Many Other 


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MM 


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36 pin 
40 pin 



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1.75 



Also available — wire wrap sockets, 
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Electronics 



P. 0. Box 82 2- Belmont. Ca. 94002 

PHONE ORDERS WELCOME 

(415] 592-B097 



76 



73 MAGAZINE 



Keith Woodward VK2BAU 
Flat 28, 48 Morehead St 
Red fern 2016 
New South Wales, Australia 




146 



MH 



z 



MOBILE 



AN 



FNNA 



Here is a very inexpensive antenna which uses your 
car body as the ground. 



In Australia, mobile operation on 1 46 
MHz FM, using discarded mobile radio- 
telephones, is very popular, Ag with all 
amateurs the author has given considerable 
thought to getting the most signal out with a 
minimum outlay- The units available re- 
stricted the actual power available, without 
major modifications, so the next important 
link in communications, the antenna, re- 
ceived my attention. 

The most used antenna is the quarter- 
wave whip. This antenna leaves a great deal 
to be desired especially if it is mounted on 
the mudguard where shielding reduces its 
effectiveness. After all, not all of us like to 
carve holes in the center of the roof. An 
antenna which has some appeal is the coaxial 
dipole, an efficient radiator, which could be 
elevated above the car roof to minimize 
shielding. However, this antenna has prob- 
lems with feed lines in its standard form. 
Below is the story of how these difficulties 
were overcome to produce a gain antenna 
utilizing a cheap base connector. 

The normal coaxial dipole consists of a 
quarter- wave whip on top of a metallic 
supporting pole which is metallically and 
electrically joined to a quarter-wave sleeve. 



The coaxial cable inner is connected to the 
bottom of the whip and the braid to the 
pole and the sleeve. This system produces a 
strong ground wave but also produces stand- 
ing waves on the supporting pole. By placing 
radials a quarter-wave below the bottom of 
the sleeve they act as an rf choke to reduce 
the standing waves on the pole. A secondary 
effect of these radials is to utilize the 
standing waves to reinforce the original 
radiated signal. Thus the radials add to the 
gain of the antenna. 

If such an antenna could be used with the 
car body acting as the ground plane we 
would achieve a very efficient mobile radia- 
tor. The feed impedance of a coaxial dipole 
antenna is a nominal 75H and normally it 
would be necessary to feed the coaxial cable 
up the center of the supporting pole to the 
feed point. This necessity would make the 
antenna a rather messy one to attach to a 
car. On studying the suggested antenna it 
was realized that the distance from the 
ground plane to the feed point is approxi- 
mately a half wavelength. 

One fact emerges from this discovery. 
Because impedances are repeated each half 
wavelength on a transmission line it is 






OCTOBER 1974 



77 



PL-2S9 





BRASS MAST, £ H> 





BRASS SLEEVE, 1* 1,0. 



BRASS RING 



RING SHOULD SLIDE INTO 
SLEEVE FORMING A VERY 
TIGHT FIT. 



FIBER PLUG SHOULD SLIDE 
INTO MAST FORMING A VERY 
TIGHT FIT,, 



57 



C 



2= 



^ 



BRASS fiOO 



-y DIM 



^ 



32 



DIA, HOLE 




FIBER PLUG 



Fig, 1. Sub-assemblies for 146 MHz coaxial dipole 
Items shown are not drawn to scale and most 
critical dimensions have been left out 

possible that a feed point impedance at the 
ground plane could be repeated in impe- 
dance at the junction of the whip and sleeve. 
However, because of velocity factor effects 
on transmission lines, it would be impossible 
to use ordinary coaxial cable for this pur- 
pose. The transmission line must have a 

velocity factor close to unity, 

A transmission line with a velocity factor 
of unity is air spaced coaxial cable. By now 
the reasoning may have become clear to the 
more astute . The support pole can become 
the sheath of an air spaced coaxial cable so 
that a wire fed centrally through its half 
wavelength will produce the required unity 
velocity factor half wavelength transmission 
line. The impedance of this line is not 
critical as it will repeat the impedance seen 
at one end to the other. This means that the 
materials used can be governed by the 
fittings and facilities of your own workshop. 

In practice the inner conductor will need 
the support of two or three beads along its 
length. These could be pieces of poly from 



coaxial cable. This will tend to reduce the 

velocity factor very slightly. The bottom 

section of the antenna due to end effect is 

slightly less than a half wavelength. You will 

find that these two factors just mentioned 

tend to cancel each other out. 

There are many ways of fabricating the 

antenna and one suggested method is shown 
in the accompanying sketches. For economy 
the PL239 plug assembly was chosen for a 
base connector. The half wavelength 
supporting tube is brazed or soft soldered to 
the tailpiece of the connector. Incidentally, 
pick a connector with an insulation material 
that is not susceptible to heat. Also note 
that the bottom section length should make 
due allowance for the length of the con- 
nector used. A brass spacer ring is brazed or 
soft soldered to the top of the support pole. 
This brass ring is drilled and tapped at three 
or four points to allow the brass sleeve to be 
screwed into position. 

The inner conductor and whip is made 
from one piece of material. One end of this 
material is reduced to fit into the inner of 
the connector. Slip the support beads on the 
inner conductor, insert it into the support 
pole and solder the end to the connector. 
Next a small fiber, or similar material plug is 
fed over the whip end of the inner con- 
ductor and pushed to the top of the support 
pole. A generous application of an epoxy 
based glue at this point will complete the 
construction. 

When installed the SWR may be shifted 
slightly by varying the length of the whip 
section. On the few antennas made by the 
author the whip length was deliberately 
made long, about 22 inches, and then 
reduced bit by bit till a minimum SWR was 

achieved. 

In-operation tests were made by compar- 
ing against a standard quarter-wave whip, 
both mounted on the center of an auto- 
mobile roof. In all tests, changing from the 
quarter-wave whip to the coaxial type an- 
tenna more than doubled the limiter current 
of the FM receiver used for signal strength 
comparisons. Some of these antennas with 
normal quarter wave radials have been used 
as home station antennas with excellent 
results. 

. . .VK2BAU 



78 



73 MAGAZINE 



Bill Hoisington KICLL 
c/o 73 Magazine Inc. 
Peterborough NH 034S8 



Miniboxi 




th 




1.65 MHz 




(432'er Series) 






Here is a 1.65 MHz i-f strip, all built 
into a rninibox, for use with VHF 
converters. 

Why build something like this? Well, 
I made the unit to go with my 432'er 
transceiver, but it certainly will work with 
just about any HF or VHF converter to 
provide good selectivity and high i-f gain 
along with adequate image rejection. Be- 
sides that, how many good transistorized 
i-f strips are there around these days? 

The two transistors in this amplifier give 
you all the gain you can ask for when used 
with a low frequency (135 kHz) i-f ampli- 
fier. This is where you really pick up your 
selectivity, 

As usual for me I first built the unit on 
a breadboard where I could get at it and 
experiment with all of the components. 
There were enough headaches in getting 
this to work so I was glad that I hadn't 
started out cramming it all into a minibox. 
Once I had it working smoothly and had all 
the bugs out I did rebuild the finished 



project in a little box. Strange to say, it 
still worked! 

Selectivity is important for two reaons: 
first, when used alone, and second, for 
avoiding images when used with the nar- 
rowband 135 kHz i-f. There are some 
natural frequencies for i-f use that, because 
of allocations, are better than others. 455 
kHz is an important one, but mainly for 
broadcast receivers, because images can be 
troublesome at 28 to 30 MHz in amateur 

use. 

The next one up is at 1,65 MHz, just 
outside the broadcast band, giving an image 
more than 3 MHz away from the desired 
signal. A number of low-cost receivers have 
used this i-f; however, the selectivity of 
these receivers has generally suffered when 
used on the crowded bands, or even on 
VHF openings. 

So in this 1.65 i-f we have not put in 
crystal or ceramic or mechanical filters 
because of cost, but rely instead on the 
addition of the 2 x 4 in. minibox converter 



OCTOBER 1974 



and narrow band i-f to supply the selec- 
tivity needed. Needless to say at 135 kHz 
you can get almost any degree of narrow 
bandwidth you want to use on 432 and 
1 296 MHz, or any other VHF band. 

Fortunately we have found an i-f trans- 
former core design that makes homebrew 
winding at 1.65 MHz easy and still results 
in adequate selectivity. See Tables I and II. 

Keep in mind that in a triple conversion 
receiver, as well as in a front end, image 
response is at times very important. If the 
1,65 MHz i-f does not have sufficient 
selectivity the 135 kHz image only 270 
kHz away could come through it. The 
three tuned circuits used, one of them 
being in the output of the 28 to 30 MHz 
tuneable converter, form a 1,65 MHz i-f 
that does the job in good style, 

Gain design 

As mentioned before, it is easy in the 
432'er to actually suffer from an excess of 
gain unless proper controls are used. With 
two low-noise rf stages in front, a good 10 
meter tuneable front end used for tuning 
and conversion at 28 to 30 MHz, two 
stages on 1.65 MHz, and then two more on 
135 kHz, there is more gain than needed, if 
all are run full on. 

Inasmuch as the experimenter builder 
may at times also want to use some of 
these units separately for various tests or 
operations, each of them should be subject 
to good control for use alone with full gain 
or in the complete triple conversion re- 
ceiver of the 432*er. In the latter use 
adjustable gain to suit the individual opera- 
tor's taste concerning interstation noise is 
needed. Two methods of gain control have 
been tested and they are shown in Fig. 1 
and Fjg, 2, They both work well, as you 
will find, and can serve to set the inter- 
station noise. The one shown in Fig, 1 is 
the usual type with the control in the 
emitter of Ql . The method shown in Fig. 2 
controls the base bias and gives slightly 
more avc action. It is really a matter of 
whether you have a IK pot or one of 10 to 
25K on hand, 
I-f Transformer Primary Winding Tests 

Having the circuit on the breadboard for 
the second time, the best windings for the 



1.65 MHz i-f transformers were investi- 
gated, and this turned out to be very 
worthwhile, allowing good design control 
over the question of neutralization which 
now turns out to be unnecessary. 

There are four main parameters in the 
i-f transformer to start with. First, the size 
of the wire, the number of turns, the value 
of the resonating capacitor, and then the 
number of turns on the secondary going to 
the following base. 

We have avoided a tapped primary for 
the sake of simplicity, using fewer turns 
and a bigger capacitor to match the collec- 
tor impedance. However, you can go too 
far in turns reduction. When we went to 
only 15 turns, which needed 1700 pF for 
resonance at 1.65 MHz, the gain was down 
a little. 

The size of the wire showed up as more 
important. I can just hear i-f transformer 
people laughing plenty at some of these 
remarks, but do they give you all the real 
lowdown for homebrew winding? 

I had been using No. 38 wire and then 
No. 34, and finally went up to No. 30 in 
size, just to see. I saw, all right. The Q 
came up to where the internal transistor 
feedback caused Ql to oscillate when its 
base and collector windings were tuned to 
exactly L65 MHz, See also Table I on the 
influence of the number of turns of the 
base winding. 

A good balance was finally reached, as 
shown in Table L The number of turns is 
not critical, it's just that there is a region 
where everything, such as af, selectivity, 



+ I2V 





Fig. 2. 
Emitter gain control. 



Fig. 2. 
Base gain con troL 



80 



73 MAGAZINE 




AF 
OUT 



+ 12 V 



Fig. 3. Af circuits. 

avc, no feedback, but still plenty of gain, 
are all at their best. You could get a little 
more gain with neutralization, but you 
don't need more gain. 

Hope yours sounds as good when you 
build it. 

The i-f transformer secondary windings 
were quite a revelation, even after building 
dozens of i-f transformers from 120 MHz 
to 135 kHz. 

Here is the answer to feedback, oscilla- 
tion, and neutralization, In the past I 
generally wound on a few turns, say five. 
For this secondary, L2, which feeds into 
the base of the next transistor, it worked, 
and I let it go at that. After all, there's 
plenty else to do in a complete low-noise, 

solid-state, high selectivity, triple conver- 
sion receiver on 432 MHz! 

Having a second breadboard 1.65 MHz 
i-f running just to be sure of all the 
components going into the smallest mini- 
box used here so far, I thought it might be 
a good thing to try a series of secondaries 
and see just what would happen. Lucky I 
did, as you will see. Referring to Fig, 8, the 
secondary winding L2 was varied with 
results as shown in Table L 

Table I tells the story. You can have 
both gain and absence of neutralization, if 
you just work at it a Little. 

"Boughten" I-f Transformers 

The above tests on windings brings to 
mind right away a big question. Has the 



manufacturer put out his i-f transformer 
for an unneutralized stage or a neutralized 
one? I don't know! This whole subject is 
quite an important one and takes up the 
full time of various coil engineers around 
the country as well as the part time of a lot 
of device application engineers. 

Once again the RCA Handbook on 
devices (I don't work for RCA, It's just a 
real good book!) is very explicit on the 
turns ratios of 455 kHz i-f transformers for 
transistors (but not the number of turns, 
unfortunately) in their application section 
on good low-cost receivers. Don't miss that 
section if you're going to build, I like 
especially their easy-to-do solution to over- 
loading in a popular broadcast set. 

Good Demodulation 

This is something given considerable 
preference here because I like Admirable 
Modulation. It is possible to get to 432 
with SSB, but look at all the converters 
you need! If they're low power you need a 
lot of amplification after you reach 432. If 
they're high power they cost like sin. And 
talk about touchy tuning. Wow! 

So, more hours were spent getting good 
af out of diode Dl 5 without overloading or 
blocking, on a loud local. This is also part 



Table II. Winding data, 
14 transformers. 



Coif 


Size 


No. 


of 


How 


In if 




Wire 


Turns 


Wound 


xfmrs 


L1 


30 ( 
DSC 


21 




About 2 layers, 
progressive. 


1 


L2 


34 
DCC 


4 




On LI 


1 


L3 


34 
DCC 


24 




As LI 


2 


L4 


38 
DSC 


20 




Over 
L3 


2 


L5 


38 
DSC 


2 




Over 
L6 


2 


L6 


38 
DSC 


15 




Over 
L3 


2 



Table I. Tests on L2. 



urns 


Gain 




Feedback 


1 


Not enou 


gH 


None 


2 


Better 




None 


3 


Almost 
enough 




None 


4 


Best 




None 


5 


Same 




Regeneration 
shows 


10 


Same 




Oscillates 



Notes. 1, Cup cores are from Miller IOC if 
transformers with all original wire and frames 
stripped off. 

2. L5 has tape tabs for identification. 

3. L6 has tape double tabs for identification. 

4. Colls are wound on impregnated paper forms, 
5/16 o.d., that slip over center post of cup core 
after winding . 

5. Light application of High Q coil wax after each 
winding (melt onh 



OCTOBER 1974 



81 



of the avc problem as outlined in the next 
section. Figure 3 shows the final af section, 
and it works well also. When the af diode 
was connected to the top of the collector 
winding L3, it seemed to produce a little 
distortion on loud signals, so a separate 
winding was installed in i-f transformer 2 
and it really did the trick. Better tuning 
and selectivity and plenty of af and avc 
resulted- 

From the way it works and sounds, this 
is liable to be my i-f output circuit from 
now on. 

More and Better Avc 

We really worked on this item also, and 
it paid off nicely. Remember, we're trying 



l-F XFM* NO I 



I-F XFM* NO f 




.01 



ffo 



Fig. 4. Ave circuit. 

to stick to a fairly straightforward circuit, 
just two diodes without a separate avc 
amplifier. Figure 4 shows details of the avc 
circuit that works like a charm. The trick 
of course is to be able to hear those 
stations in the next state (geographic) and 
still demodulate properly on a strong local 
without distortion. 

Some like forward avc and some like 
reverse avc, and there are of course special 
reasons for both which need not concern 
us here. Reverse avc was always used with 
tubes, where the remote cutoff tubes were 
evolved just for that purpose. They were 
the opposite of steep slope jobs and used a 
variable grid winding inside the tube. 
Worked fine on loud locals. How about 
soipe transistors like that, RCA or Motor- 
ola? Maybe they already have them? 

I go for reverse avc myself, because it 
just seems natural to cut down the current 
to lower the gain. Also maybe because 
most of the rigs I'm building have battery 
operation in mind. 




Fig, 5. Test for proximity of i-f transformer one 
to i-f transformer two. 



In the circuit shown in Fig. 4, Ql runs 
around 4 to 5 mils of current on no signal 
and drops down to 20 or 30 fiA on locals. 
The dc balance for these conditions was 
worked out with a bunch of pots all over 
the place checking out the best values for 
Rl , R2,R3, C1 5 C2, etc. The circuit calls for 
four windings on the last i-f transformer 
but is well worth it and not difficult. 

I started with the af diode DI connect- 
ed to the LI winding of Fig. 4, but soon 
found that better all-round operation re- 
sulted from a separate winding for the af 
which also made for better avc action. 

Referring to Fig. 4, positive voltage goes 
to the base of Ql through Rl, is stabilized 
on ct no signal" with resistor R2 and de- 
coupling resistor R3, the whole line going 
to ground through D2. Negative voltage is 
developed when an i-f signal arrives at D2, 
and is sent through the avc line to the base 
of Ql, driving the current down to as low 
as 20 juA on a local* 

Size Reduction 

We're cutting down on the size a little 
with concentration on flatter packaging. A 
variety of real small size miniboxes, per- 
haps with adjustable partitions inside 
would be handy (Hey, BUD!). 




BOARD SIZE -2 in * 4 in 



\Z VOLT 
BAT. PLUG 



Fig. 6, Layout completed 1.65 MHz amplifier. 



82 



73 MAGAZINE 



SIGNAL 
OC^fPATOB 

l €3 UHj 



AF OUT 




12 VOLT 
BAT. PLUG 



•5" METER 
(EMITTER CURRENT) 



Fig. 7. Final test setup. 1.65 MHz i-f.Ati external 
components shown have to be unsoldered to 
install amplifier in box. 

The gain control potentiometer is the 
biggest component here. However, Laf- 
ayette Radio comes through again on 
miniature components with their series at 
only 59^ and only 5/8 ths in. diameter. 

The four jacks are of course single hole 
mounting types which take up a minimum 
of space inside. 

My favorite .021 pins are used for 
terminals as usual, hammered into .020 



holes drilled with a No, 76 drill through 
,035 fiberglass strips, with .005 fiberglass 
underneath to keep the pins from shorting 
to the baseboard, the whole cemented 
down with low-loss coil cement, 

A test as in Fig. 5 was made to see how 
close to each other the i-f transformers 
could be placed with the following results; 
2 in. okay; 1 in. okay; Vi in. beginning to 
show a little regeneration; 3/8 in. more 
regeneration; 1/8 in. oscillation from feed- 
back. With the collector winding in L2 and 
the base winding in LI, this is an important 
consideration, especially for close pack- 
aging. In Fig. 5, the spacing is identified as 
"D." No trouble was had in this unit, as D 
equalled almost 1 in. Note that with 
magnetic coupling such as at 1/8 in, neu- 
tralization would be difficult if not impos- 
sible. An attempt was made to reduce the 
length of the box for this i-f unit, without 
success, because the two i-f transformers 
and the two trimmers are simply too big. 
However, 2 x 4 in, is certainly small 
enough for now. 

Assembly and Layout 

I generally have some sort of trouble to 
relate, but I guess the use of the second 
breadboard and checking of components 
was a good plan. 




NOTES- L SEE TABLE 2 FOR i-F XFWR WINDINGS. 
2 T *$* METEft CURRENT AT ZERO SIGNAL 

IS 4 TO 5 rnA, 
3. THE POSITIVE VOLTAGE AFTER RIO 

*S A80UT II VOLTS, 



Fig. 8. Complete cfrcuit 1.65 MHz i-f. Ql mid Q 2 are Motorola HEP 5 5. 



OCTOBER 1974 



83 





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The HEPSS's with their base pin in the 
middle posed a small problem, but by 
twisting the leads around a little as you can 
see in the layout, Fig, 6, everything came 
out fine. 

The key components such as diodes and 
i-f transformers were tested on the bread- 
board, so they naturally worked right 
away. This is mainly just a matter of 
avoiding soldering and unsoldering com- 
ponents in a very small area later, which 
makes for a neater final job. 

Figure 6 is a faithful picture of the way 
the components are placed on the base- 
board, and also shows the actual open 
spaces. This could lead to thought of 
further size reduction, but there we're 
getting near the use of a microscope, and 
that is quite another story. 

Final Testing 

With everything in place and ready to 
go, signal generator, af test amplifier, S 
meter, and battery plug connected, the 
"on" switch was ready to be thrown, as in 
Fig. 7. And this is just the time when I 



always get the jitters! Will the to 100 
milliammeter in series with the 12V bat- 
tery slam over against the pin? Will Ql and 
Q2 go West in a few milliseconds? Will a 
dull silence come out of the loudspeaker? 
However, the moment a few mils show 
steady, my nerves settle down and Fm 
good for hours of alignment, gain-setting, 
testing, etc. 

This one came on right away, tuned up 
fine, and only needed a little jiggling of the 
value for Rl to behave perfectly. 

After everything is running, proper avc, 
good adjustable gain and af output, and the 
frequency centered on L65 MHz, the 
baseboard can then be mounted in the box 
and the wires soldered back onto the jacks 
and control. One final operating check and 
tuneup in the box and there you are. 

The complete circuit is shown in Fig. 8, 
and it's a good one. 

Conclusion 

This little box replaces another bread- 
board in the 432'er receiver, and also 
makes a good general purpose i-f around 
the shack. . . . K1CLL 



84 



73 MAGAZINE 



Gabe Gargiulo WA1GFJ 

1 7 Whitney Street 

East Hartford CT 061 18 




HOLD ON 
THAT RIG! 



While looking through the ham ads 
recently I was stunned to see at 
least three ads of equipment for sale, with 
the excuse of "college expenses/' Now just a 
minute! How much do they expect to get 
for a used station? $1,000? $2,000? It 
would have to be some station to sell for 
that much, second hand. And how far would 
one or two grand go in college? It might pay 
the tuition for one year in a small percentage 
of colleges. Selling a station when you need 
cash is not the answer. 

I was greatly tempted a few years ago to 
sell some of my equipment (Swan 500C, 
Swan 400, Gonset GSB 2, two'er, D104 
mike) simply because I needed the money 
due to marriage, bills, and a baby, all of 
which cost more than any college. 

But, being a true ham, I kept convincing 
myself to hold on to that radio gear — things 
were bound to get better. They did, thanks 
to a programming job, and now I am back 
on the air and into 2 meter FM. If I had sold 
all my gear, I would still have the bills, but 
no rig, and a sorry ham I would be! 

Look at it from a financial point of view. 
Sooner or later you will gel out of your 



financial difficulty and will need to get back 
on the air. Then you will have to buy all new 
gear, which will cost you much more than 
you got for your old equipment. If you had 
taken out a loan when you needed the 
money, you would be ahead of the game 
(and still have your rigs). 

Have you ever found out how much you 
can get for your old rigs? I did. A local 
distributor offered me $75 for my Swan 400 
that I bought for about $450 in 1967. 1 was 
offered the same for my GSB 2. It's not 
worth it to sell them. 

So, whatever the reason you are thinking 
of selling out, don't. You will get over the 
financial crisis and the ham radio bug will 
bite you again. If you don't need the money 
and have just lost interest in ham radio, 
don't sell out Why not let someone benefit 
who is still interested in it? How about 
letting a teenager borrow it, or giving it to a 
radio club or to someone in DX-land? 

Don't get out of ham radio - you may 
regret it if you do — but you'll never regret 
it if you stay with it. 

. . .WA1GFJ 






R.C. Altman WA6AXV 

1 053 Shrader Street 

San Francisco CA 94117 



IT'S 




CALL 



QST, QST, QST— Our new WR call has 
arrived/' Thus our trustee, WA6AGA 
announced the event Tuesday afternoon, 
June 26th, just 5 days before the July 1 
deadline, and 3 days before the announce- 
ment from the FCC of a 60 day extension. 

I'm sure the members felt almost as they 
might have at the announcement of the 
uncomplicated birth of a son. After months 
of trying to meet FCC's complicated require- 
ments for a repeater license (and 2 sub- 
missions), the best repeater in all of Six 
land, WB6AAE, had its new WR call. The 
trustee, Al Nielsen, first thought not even to 
open it, "let's have an unveiling ceremony," 
but his curiosity got the better of him, plus 
he decided having the new LD.er wheel 
ready would make a better ceremony. One 
member promptly organized a pool of 
guessing the new call at 10c an entry, to be 
mailed to him not later than Saturday June 
30, Pay-off to be at next club meeting July 
27th, thus allowing for slow mail delivery. 

Al immediately contacted the program 
chairman WB6GWQ Roy and said, "devise 
some kind of ceremony — probably upon the 
hill at the repeater site for this Sunday for a 
change of call/' 

Being one of the top program chairmen in 
the country, he immediately threw his 
hair-trigger brain into gear, phoned a brace 
of members for assistance, and pulled off 
another of his brilliant schemes. With 
plenty of on-the-air publicity during the 
next 5 days, we had 55 people up on the hill 
for the ceremony to take place at high noon 
on July 1. 



A committee of two was picked to design 
a special QSL to be issued to any check-rns 
during the first 8 hours of operation under 
the new call. Tape recorders were hooked 
up to record the requests. Champagne and 
hot dogs were purchased, movie cameras 
were arranged for— a bed sheet was requisi- 
tioned for a banner— sprayed on it ahead of 
time was "WR6 " and the big day arrived. 
Beautiful weather, bright, not a cloud in the 
sky—perfect! The program chairman Roy 
tried to take credit for that too. 

Beginning about 9:00 a.m. the trek was 
on from all over the San Francisco Bay Area, 
Many of the members even had breakfast 
together and went up into the Berkeley hills 
in a caravan. Some members drove 50 miles 
one-way from San Jose to be there. 

The banner was strung up, ready to be 
raised on high, the hotdog broiler was 
plugged in and cooking, the champagne 
was on ice. Two of the more rotund mem- 
bers settled a long-standing argument as to 
which one could squeeze into the narrow 
space- behind the repeater cabinet (they 
both did — so we still don't know which one 
is heavier). 

A public address system was set up be- 
cause only about 6 or 8 people could crowd 
into the shack to witness the changing of 
the I.D.er wheel, a running commentary 
was being given over the repeater by Little 
John WA6TKP; for the benefit of all not able 
to be there. Final entries into the dime pool 
were filed along with their guess at what the 
new call would be. 

A little bit of history of the repeater was 



86 



73 MAGAZINE 



announced over the p. a. system and over 
the air. It was first put on the air in 1962, 
first meetings were held in whose living 
room, and now we have 155 paid-in mem- 
bers, etc. 

At 11:55 a.m. the last ID, of WB6AAE 
went out over the air automatically, the 
wheel was removed, to the sound of taps 
bugled by Antioch John WA6ENM, the new 
wheel was installed and we waited — and 
waited — actually only about one minute, 
but it seemed like hours, then there it was— 
WR6ABM! Promptly as 12 noon, July 1, 
1973. Antioch John promptly blew charge 
and shouts went up, ABM was sprayed on 
the bedsheet banner and it was raised about 
30 feet into the air with feelings similar to 
those when you see the Stars & Stripes in a 
solemn moment. The air was filled with 
many many calls all at the same time, 
everybody listening trying to be first on the 
repeater with its new call. To listen to the 
tape now, it was mass bedlam, but in a 
minute they started settling down and 
calling in — in a more orderly fashion, 
placing their call and address on the tape for 
their request for the new QSL card. The last 
time I heard the total count— 210 names 
and addresses were recorded. 

Up on the hill, champagne corks were 
popping as much as 20 feet into the air. 
Everybody there had champagne and over 
200 hotdogs were consumed in 30 minutes. 

The trustee, Al Nielsen, WA6AGA was 
showered from behind with champagne as 
he retired the old wheel into what was called 
a cavity, but sure resembled a wastebasket, 
and burned. 

One member, Lou WB6TXD surprised all 
ofusbybringinga beautiful cake decorated 
like a birth announcement that said "IT'S A 
CALL/' Movies of the entire proceedings 
were made by Sunset John WA6DPJ and 
shown at the next meeting, for the benefit 
of those that couldn't be there. He did a 
beautiful job of editing the film. 

The dime pool contained $1.90 since we 
only had 5 days to publicize it, and was won 
by Clem WA6AVM. He picked the correct 
call because of his own call. A good time 
was had by all! 

WA6AXV 



CALL 
BOOK 




When you want 
an authoritative, 
up to date directory 
of licensed radio 
amateurs 

It's the 
CALLBOOK 

Over 210,000 QTH's 

in the DX edition 

DX CALLBOOK for 1974 

3>o.95 



• "•' jTjtefl : 




Over 285,000 QTH's 

in the U.S. edition 

U.S. CALLBOOK for 1974 

$9.95 

See your favorite dealer or Send today to 

(Mail orders add 50e per CALLBOOK 
for postage and handling) 



RADIO AMATEUR 






lib 



oo 



k 



INC. 



Dept b 925 Sherwood Drive 
Lake Bluff, III. 60044 



■ 



OCTOBER 1974 



87 



r 




VHF Two-Band Transceiver 

for 2 and 1 1 4 meters with 

Digital Frequency Synthesis 

The new CST-50 Two-Band Transceiver provides coverage of two complete 
amateur bands with all the features needed by most operators. Imagine! The 
two most popular VHF bands in one rig with Phase Locked Loop frequency 
synthesis. In the CST-50 all frequencies are generated digitally by reference to 
one highly accurate and easily adjustable crystal As soon as a new repeater 
is on you can use it, no waiting for crystals. Write for further information. 



Covers entire 2 meter and 1 [ A meter bands 

Covers MARS, CAP and CD frequencies from 

142 to 149.995 MHz 

Full digital frequency synthesis with 5 kHz steps 

Lighted thumbwheels for night mobile operation 

No crystals to buy — ever 

Built-in repeater offsets of 600 kHz, 1 Mhz 

and 1.6 MHz 

25 watts output on each band 

No transmitter retuning across either band 

FM-AM receiver 

8 pole crystal filter 

Front mounted speaker 



PTT microphone and mobile mount included 

Operates on 12 volts DC 

AC supply available 

Accessory connector for tone burst and tone 

coded squelch 



CST-50 two -band transceiver 
CPS-6 AC power supply 

MADF IN USA by 



$769.95 
$119.95 




COMCRAFT 

P.O.BOX 266. GOLETA. CA 93017 



88 



73 MAGAZINE 



EmiJ Hrivnak W3HPX 
147 Penn Lear Drive 
Monroeville PA 15146 




MOSKEY 



A PROGRAMMABLE IAMIC CMOS KEYER 

Part2 



Part of this article published in the June 
issue of 73 described the basic 
keyer portion of MOSKEY. In Part II I will 
describe how the memory circuit works and 
how Morse code is encoded to obtain high 
density storage in memory. 

Memory Coding Scheme 

A considerable amount of time was spent 
to determine the most efficient way to store 
the code into the memory to conserve 
memory space. When MOSKEY was first 
designed the largest static RAM available was 
a 256 bit TTL RAM. Just a 3 by 3 CQ sent 
twice would use up 680 bits of memory. 
Having only 4 RAMS, 1024 bits of memory, 
on hand, that didn't leave much room to 
program in other phrases. I decided the 
repeat capability was a must and began to 
look for a way to more efficiently store the 
code in memory. Now with 1024 bit static 
RAMs available memory space is not so 
much of a premium, but the same coding 
scheme is used here as originally designed. 
The simplest way to store the code is to 
sequentially store Vs and 0*s in memory, 
with a 1 representing an output, and a 0, no 



output. The letter "A" would be stored as 
10/1110. CQ with letter and word spacing 
would be stored as 1 110 /10 /l 1 10 /I0 /00 
/1110 /1 110 /10 /1110 /000000/ using 34 
bits of memory. One method to conserve 
memory space would be to store only 2 
ones in memory for a dash, instead of 3 
ones , and let the keyer automatically fill in 
the third time unit when sending a dash- 
Likewise only 2 zeros could be interpreted 
as a letter space, again letting the keyer fill 
in the missing space unit. A word space 
could be stored as 3 zeros in sequence and 
the keyer could lengthen it out to a 7 unit 
word space. CQ would then look like this 
1 10/10/11 0/ 1 0/0/ 110/1 1 0/ 10/11 0/00/ 
using a total of 24 bits of memory space. 
Since there are only four instructions to be 
stored in memory: a dot, a dash, a letter 
space, and a word space, I decided that 
storing a two bit op-code, like a computer 
instruction, could be decoded into the four 
instructions. The op-code is read out of 
memory two bits at a time and decoded to 
control the keyer. The memory actually 
consists of 2 memory ICs operating side by 
side, with one op-code bit coming out of 



OCTOBER 1974 



89 



CLOCK 



9 91T 

BINARY 

COUNTER 



EO 



KEY 



OUTPUT 
FF 


SIDE TONE 


XMTR KEYER 



ADDRESS 

SELECTION 

SWITCHES 



COUNTER 

ADVANCE 
CIRCUIT 



i 



KEY CIRCUIT 



STOP 

STORE 

SWITCH 





I 



PRESET 
SWITCH 




MEMORY 
ADDRESS 

COUNTER 
U24,25 ( 26 



MEMORY 
U32 t 33 



^^^^ ^^^^ ^^^^ ^^^^ 

3 5 7 

^_^_ ^_^ ^_^_ ^_^ 



DISPLAY 



STOP + REPEAT 
INSTRUCTION 
GENERATOR 




REPEAT 

STORE 

SWITCH 




PROGRAM 
SWITCH 



Fig. 6. Signal flow for programming memory. 



memory A, and the second op-code bit 
coming out of memory B. Let the op-code 
assignment be the following: 

OP-CODE BIT OP CODE BIT CHARACTER 
A B 

Word Space 

1 Dash 

1 Dot 

1 1 Letter Space 

Then CQ reduces to the following: 

AB AB AB AB AB AB AB AB AB AB 
10 01 10 01 11 10 10 01 10 00 

using only 20 bits of memory. This is the 
way MOSKEY stores code in memory. MOS- 
KEY is capable of storing 1024 characters, a 
character being a dot, dash, letter space, or a 
word space. The memories are 1024 bit 
N-channel MOS devices. They are CMOS 
compatible if the CMOS is operated at 5V, 
They were priced in the $70 range when first 
introduced a year ago, but have come down 
to $12 to $15 each now. Hopefully they will 
drop in price even more as the price of 
CMOS devices continues to decline. 

Programming Memory 

Figure 6 shows the block diagram of the 
keyer with the additions necessary to pro- 
gram memory. The encoder circuitry en- 
codes dots, dashes, letter spaces, and word 
spaces into the proper op-code for storage in 



memory. The memory address counter is a 
10 bit binary counter which sequentially 
accesses the 1024 locations of memory. 
After each instruction is written into 
memory the memory address counter is 
incremented by one. 

The keyer is placed in the programming 
mode by turning on the PROGRAM switch. 
The memory address counter can be preset 
to any starting location by selecting a 
number on the address switches and pressing 
the PRESET button. This permits sequences 
to be stored anywhere in memory. The 
counter will start from the location it was 
preset to and continue from there. The 
sequence desired is loaded into memory by 
simply sending it on the key. As each dot, 
dash, letter space, and word space is sent, it 
is encoded and stored into memory by the 

write circuitry. When no further entries are 
made from the key, the keyer will store the 
word space into memory and enter the idling 
mode. Long gaps between words are not 
programmed into memory. Specific combi- 
nations of op-codes (to be discussed later) 
are used to program a stop instruction or a 
repeat instruction in memory. This is accom- 
plished by pressing the stop store switch or 
the repeat store switch. The instruction will 
be written into memory and the memory 
address counter advanced by 1 . 



90 



73 MAGAZINE 



The display is used to see what location 
in memory is currently being used, By 
jotting down the starting location of each 
sequence programmed in memory, you can 
preset the address counter to that Location 
and have the keyer send any one of several 
sequences stored away. 

When programming memory, as each dot 
or dash is sent from the key, during the last 
bit time of the space following the dot or 
dash, when HOI is high, CLOCK 2 generates 
a write pulse to the memories and stores the 
op-code in memory. A new character is then 
started from the key- EOI DELAYED BAR 
is low during the first bit time of the new 
character and is an enable to advance the 
memory address counter at this time. The 
memory is then ready to have the next 
op-code stored into it during the last bit 
time of that character. When no further 
entry comes from the key, the keyer enters 
the letter space mode. During the last bit 
time of the letter space the op-code is stored 
in memory. Now comes a decision. If a key 
entry comes along, then it was really a letter 
space and the memory will be advanced 
during the first bit of time of the dot or dash 
being sent. If no key entry occurs then the 
keyer enters the word space mode to time 
out 4 more spaces. The memory is not 
advanced this time and during the last bit 
time of the word space the word space 
op-code is written over top of the previously 
stored letter space instruction. Then the 
memory is advanced during the next bit 
time* When the keyer is idling no writing or 
advancing of the memory takes place. 



CLOCK 



Sending From Memory 

Figure 7 shows the signal flow for reading 
code out of memory. The starting location 
of the sequence is selected by the address 
switches and loaded into the memory 
address counter by pressing the PRESET 
switch. The counter will count up from this 
location as the code is sent from memory. 
Pressing the START button starts the keyer 
and it will send code until a stop code is 
reached, or it is stopped manually by press- 
ing the STOP button. The op-code decoder 
decodes the memory outputs into dot, dash, 
tetter space, or word space commands. After 



i 



9 BrT 

BINARY 
COUNTER 







OUTPUT 
FF 


SIDE TONE 


XMTR KEYER 



START 

swrrcH 





PRESET 
SWITCH 



ADDRESS 
SELECTION 
SWITCHES 



\° 



COUNTER 
ADVANCE 

cfRcurr 

— r 



STOP 
SWITCH 




I 




MEMORY 
ADOftESS 
COUNTER 
U24,25,26 



i 



MEMORY 
U32/33 



i 



II 



■ ■ ] ■ i 
3 5 7 



DISPLAY 



OP- CODE 

DECODER 

U27 




STOP 

DECODER 

U20A,Ui7A 



REPEAT 

DECODER 

AND 

REPEAT 

FLIP-FLOP 



Fig. 7. Sending code from memory. 



U4IA,B t C 
U28B 
U42 
U28C 



the keyer starts each new character the 
memory address counter is advanced during 
the first bit time of the character so that the 
next character to be sent is available. Since 
the keyer is self-completing, once a character 
has started, the next character to be sent can 
be read from memory, be decoded, and be 
waiting for the keyer to use it upon com- 
pletion of the current character. 

The word space instruction is really a two 
phase instruction. It must generate a 6 unit 
space. When a word space instruction is 
decoded from memory the keyer first enters 
the letter space mode and the memory is not 
advanced. With the word space instruction 
still valid and LETTER SPACE FF high, the 
keyer then enters the word space mode and 
advances the memory. The control logic is 
more complicated with this scheme but the 
maximum amount of code that can be 
stored in memory is utilized. 

For those of you who peeked ahead to 
Fig. 8, the memory dot output of the 
op-code decoder is not used, it is implied 
that if the RUN FF is set then the keyer has 
to at a minimum send a dot. RUN BAR is 



OCTOBER 1974 



91 



*E* *S NEXT 
© 



HE t MODE PF STOP NErfT 



WEMORT *S NEXT 



TO ADQflESS SELECT SWITCHf$ 



KJO 200 

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NOTE 
A 

NOTE 

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C0400S 


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C04OI0 


li£^JO 


1,16 


a 


CD40JZ 


U22 


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CD4DIJ 


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021.29 


14 


7 


C0402a 


U27 


16 


6 


MC 14516 


U24. 25,26 


16 


8 


Mt U&53 


U3* 


16 


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HARASS 
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U34,J3 


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..45^ 



(10) MEMORY 04SH NEXT 
MEMORY ttS ME XT 



OP CODE 



-(g) MEMORY LS KE*T 



A SEE TEXT 

B. INTEL ?10? SIGNETICS 2602 
INTERSIL 7552 

ALL 3 ARE COMfftTlBLE 

C. 2 SECTIONS Of U28 USED IN FIGURE 13 



RAM^ROM 
SELECT 
SWITCH 



<EY NEXT 



Fig, 8. Memory section of keyer. 



used to keep the counter enabled, Fig. 3. 
The dot decode is not used, so if the keyer is 
sending from memory and no outputs of the 
op-code decoder are high the keyer sends a 
dot. A dash decode makes the counter count 
longer for a dash; a letter space decode is 
really a dot with the output inhibited; and a 
word space decode is a letter space sequence 
followed by a word space sequence. 

PROMS 

Figure 8 is the schematic of the memory 
section of the keyer. The memory address 
counter advance circuit is also included. 
U24, U25, and U26 are the memory address 
counters. Most CMOS devices cannot drive a 
TTL load so U29 and U30, non-inverting 
buffers, are used to increase the drive capa- 
bility for addressing the TTL PROMS and 
driving the displays. U34 and U35 are the 
optional PROMS installed in the keyer. They 
are 256 word by 4 bit PROMS, U36 is a dual 
4 to 1 multiplexer needed to select the 
proper PROM outputs. If you decide not to 
use the PROMS, U34, U35, and U36 can be 
eliminated Also R801 through R804 can be 



eliminated, as well as the RAM/ROM select 
switch and R807 and R808, Then connect 
RAM A OUTPUT U31 pin 12 directly to OP 
CODE BIT A U27 pin 10, and connect RAM 
B OUTPUT U33 pin 12 directly to OP 
CODE BIT B U27 pin 13. Resistors R805 
and R806 must be left installed. Ground the 
RAM chip selects U32 and U33 pin 13, 

Since the PROM is organized as 256 
words by 4 bits a multiplexer is needed to 
select two op-code bits at a time. Figure 9 
shows a simplified schematic of how this 
could be done. Assuming a sequence starts at 
location zero, all the address lines will be at 
a logic zero. The PROM will have the four 
data bits for its word zero at its outputs. 
Address line 1 is a select input to the 2:1 
multiplexer and address lines 2 through 9 are 
used to address the PROM. PROM output 1 
is selected by the multiplexer and appears as 
op-code bit A, and PROM output 2 appears 
as op-code bit B. The keyer uses this to start 
sending the first character and then advances 
the address counter to make address line 1 
go high, This causes the multiplexer to now 



92 



73 MAGAZINE 




amplifiers 




ower 




through the use of a specially selected RF relay 
■ . . activated by only one watt of RF power 
through an RF sensing circuit. During receive, 
the antenna by-passes the amplifier and is fed 
through the relay to the transceiver. Also of note is 
a reverse voltage protection diode which protects 
the power transistors from destruction in the event 
the amplifier is connected to the wrong polarity. 
TPL amplifiers are simple to install and fool-proof 
to operate* With proper care, they will provide a 
lifetime of dependable service. 



TPL brings you the finest amateur RF amplifiers 
for VHF FM available today. Only state-of-the-art 
techniques in circuit and semi conductor technology 
make an amplifier of this quality possible. 
The amplifying transistors are of the balanced 
emitter silicon power type. Each one is indi- 
vidually checked for power output and reliability 
during mismatch conditions. They are operated 
well within the factory's suggested limitations for 
added reliability and life. Most circuitry is of 
micro-strip technique for stability and broadband 
characteristics. Antenna switching is accomplished 

DID YOU KNOW... 

TPL is the largest manufacturer of accessory solid state RF power amplifiers in the world. 

TPL commercial amplifiers are used and recommended by every major manufacturer of 
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TPL's engineering staff contributed to the development of RF power transistors from their 
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TPL offers the broadest selection of RF power amplifiers. 

TPL offers the highest quality RF power amplifier available. 

TPL guarantees its amplifiers against defective parts and workmanship for a full year. 

TPL power amplifiers and repeater amplifiers are now available at your local dealer. 



• it 




COMMUNICATIONS INC. 

13125 YUKON AVENUE/ HAWTHORNE, CALIF, 90250/(213) 679-0131 



ADDRESS LINES 



I 2 3 



9 10 



ill 11 ill It 



RAM A 



RAM 



r 



ADDRESS LINES 
2 THROUGH 9 



RAM B 



PROM 



OP-COO E 
BIT A 




256 X 4 PROM 

OUTPUTS 
12 3 4 



G^i 



2 LINE 

TO 

I LINE 

MUX 



2 LINE 

TO 

I LINE 

MUX 








OP -CODE 
BIT B 



OP -CODE 

DECODER 



Fig. 9, A method to select 2 op-code bits at a time 
from PROM. 

select PROM output 3 as op-code bit A and 
PROM output 4 as op-code bit B, This 
becomes the second character for the key ex 
to send. When the keyer starts sending the 
second character address line I goes low and 
address line 2 goes high. This now selects the 
second 4 bit word of the PROM and causes 



10 


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9 H / 




1 2 1 


LcocUen 

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1 

3 


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a o o 


o 1 o 

1 i 


000? 
01 


1 

1 


1 
3 


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1 
1 1 


00 04 
0006 


3 
3 


1 

3 


2 

4 













P 1 
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0000 
000 7 


3 

3 


l 
3 


7 

4 











1 


001 
001 1 


4 
4 


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3 




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1 
1 


2 

4 







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a 1 i 


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o o a 



1 


■ 

0300 
03-0 l 


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2 


7 

4 


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1 
1 1 


0102 
0303 


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1 

3 


3 

4 





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1 
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JOS 


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1 

4 



1 t t 
1 ♦ I 



I I I 



I i a 
i i t 



1 i# 

an; 



7» 



1 
J. 



4 



Fig, 10. Table to help illustrate how address lines 
are reiated to number shown on displays, and 
actual word of PROM used. 



the multiplexer to go back to selecting 
PROM outputs 1 and 2 as the op-code bits. 
Each word of PROM contains two characters 
of code. Figure 10 helps to illustrate how 
the PROM addressing works. The RAM/ 
PROM select switch could be another dual 
2:1 multiplexer. Since dual 4:1 multiplexers 
are available these two functions can be 
combined in a single IC and Fig. 1 1 shows 
how this is accomplished. 

U34,35 



256 X 4 PROM 
OUTPUTS 



RAM 
A 

U32 



n-f 



2 5 


4 


INPUTS 


A 


1/2 OF 




DUAL 4;l 


B 


MUX 











U56 



RAM 

B 

U&33 



L_a 



2 3 

INPUTS 

i/2 OF 
DUAL 4i I e 
MUX 



OP- CODE 
BIT A 



MULTIPLEXER 
SELECT 
LINES 



OP- CODE 

BIT S 



ML 
SELECT 

A 


JX 

LINES 


INPUT 
SELECTED 








1 


1 





2 





1 


3 


1 


1 


A 




PROM 



Fig. 11. The way MOSKEY multiplexes the PROM 
outputs and selects between PROM and RAM. 

There are many versions of Programmable 
Read Only Memories (PROM) on the 
market, two of the more popular types being 
256 words X 4 bits, and 32 words X 8 bits. 
These are manufactured with aU I 's or all O's 
stored, depending on the manufacturer and 
type. They can be programmed by applying 
proper voltages and pulses and any sequence 
up to the capacity of the PROM could be 
installed in MOSKEY. Once they are pro- 
grammed, they cannot be changed back 
again. The PROMs contain nichrome fuse 
links in each memory cell which are safe 
against being blown out under normal 
operating conditions. With the proper 
voltages and current pulses applied the link 
in each desired cell can be melted open, or 
blown like a fuse, and the logic state of that 
cell changed. If you decide to install a 
PROM in your keyer give it a good hard look 
before committing to a sequence. Check and 
double check it several times as mistakes 
cannot be corrected. I do not recommend 



94 



73 MAGAZINE 



trying to program a PROM by yourself. It's 
too easy to make a mistake with so many 
bits to program and the exacting step by 
step sequence that must be followed for 
each bit. If you decide to use a PROM let 
the parts store program it for you. Some 
charge a small fee, and others will do it free. 
With the large memory size available in the 
keyer, and the ease of programming it, one 
might consider that a PROM is not really 
necessary at all. However the RAM is a 
volatile device which means that when the 
power is removed the contents of the RAM 
are lost, and without a PROM your favorite 
saying will have to be reprogrammed each 
time the keyer is turned off. 

Figure 12 shows how 32x8 PROMS could 
be implemented. Loading of the address 
lines must be watched. The 3:8 decoder 
could be a 7442 TTL chip or 4028 CMOS 
chip with inverting buffers used after it. 
Stop and Repeat Instructions 

Figure 13 shows the schematic of the 
stop and repeat instruction generators, the 
repeat circuit and the op-code encoder. With 
the coding scheme used in MOSKEY it may 



have become obvious by now that letter 
space instructions can only be followed by 
dot or dash instructions, and likewise word 
space instructions can only be followed by 
dot or dash instructions. Up to four special 
control instructions could be implemented 
by storing two letter spaces in a row, or a 
letter space followed by a word space, or 
two word spaces in a row ? or a word space 
followed by a letter space. MOSKEY uses 
two of these combinations to generate stop 
and repeat instructions. After the last dot or 
dash entered from the key is encoded and 
stored into memory, the keyer generates a 
word space op-code, stores it in memory, 
and then idles. By using a manual switch 
closure to enter a letter space or word space 
op-code into memory in the next location, it 
will be interpeted when sending from 
memory as a STOP or REPEAT instruction, 
respectively. This is done by pressing the 
stop store switch or the repeat store switch 
while the keyer is idling. The instruction will 

be written into memory and the address 
counter advanced one location. Switch 
de-bouncers and synchronizers are used on 



ADDRESS LINES 



& 




8 



AO Al A2 A3 A4 



ADDRESS INPUTS 
32 X 9 PROM 

OUTPUTS 



I 3 5 



• 



£468 



1 — 



-"CHIP 
SELECT 



1 



AO Al A2 A3 A4 

ADDRESS JNPUTS 
32 X 8 PROM 

OUTPUTS 
I 3 5 7 2 4 6 6 



Y 



2 



CHIP 
SELECT 



ADDRESS 
LINES 

I- 



2 



METHOD FOR USING 2 
32 X 6 PROMS. EACH 
32 X 8 PROM CAN 
STORE 128 CHARACTERS. 



UP TO 8 32 X 8 PROMS 
COULD BE INSTALLED 
FOR FULL CAPACITY OF 
1024 CHARACTERS, THE 
ADDRESS LINES WOULD 
REQUIRE MORE BUFFER- 
ING. A 3tB DECODER IS 
NEEDED TO ENA8LE 
EACH PROM IN 128 CHAR 
ACTER INCREMENTS, 



12 3 4 12 3 4 

A INPUTS 

DUAL 4:1 « MUX 
B 




ADDRESS 
LINES 





RAM 
B 





2ND LEVEL MUX 

OR SWITCHES 
NEEDED TO SELECT 
BETWEEN RAM/PROM 



RAM/PROM 



A 



OP -CODE 
BIT 




TO CHIP SELECTS 
PROM NUMBER 



>MST 128 CHARACTERS 
>2 2ND 328 CHARACTERS 



>B LAST 128 
CHARACTERS 



V 
8 



SN7442 OR 

CD4026 WITH 

CD 4009 

INVERTING 

BUFFERS 



Fig. 1 2. How to implement 32 x 8 PROMS in Moskey, 



OCTOBER 1974 



95 



PUSH BUTTON 
PRESET SWITCH 



RUN (13) 
WSFf(Ti)-H> 



PRESET 




MEMORY WS NEXT 
OP CODE 



TYPE 


REF 


Vet 


GNO 


C04OII 


U37,4i 


14 


7 


CD40I3 


1138,39,42 






14 


7 


CD4Q25 


U40 


14 


7 



CLOCK 



U2S LISTED ON PARTS 
LIST OF FIGURE B 



WSFF 



STOP 

STORE 

PUSH 

BUTTON 

SWITCH 



KEY DOT 
IN PROGRESS 



RAM A 
INPUT 




REPEAT 

STORE 

PUSH 

BUTTON 

SWITCH 



RAM B 
INPUT 



KEY DASH 
IN PROGRESS 



EOI ■ CLOCK 



STOP + REPEAT STORE 



Fig. 13. Schematic of repeat decoder and stop and repeat instruction generator. Also the op-code encoder. 



the stop and repeat store switches so that a 
single pulse synchronized to the keyer clock 
is generated by each switch closure. 

The repeat flip-flop is reset when not 
sending from memory. When sending from 
memory and a repeat instruction is decoded 
the memory address counter will be preset 
to the number selected on the address 
switches, which should be the starting ad- 
dress for the sequence being sent- The repeat 
flip-flop will also be set. The keyer will 
return to the beginning of the sequence and 
send it again. When the repeat instruction is 
reached again the second time through the 
sequence, the repeat instruction is ignored. 
The memory address counter is advanced 
one more location skipping over the repeat 
instruction to that the keyer has the next 
valid dot or dash instruction ready for when 
it is needed, (The keyer is self-completing a 
word space at the time the repeat instruction 
is decoded and inputs to the 9 bit counter, 
the dot, dash, etc., generator are being 



ignored until the end of the character, so the 
memory advance circuit in the keyer can 
advance the memory beyond the repeat 
instruction and not cause any abnormal 
operation in the keyer* All characters will 
still be perfectly timed.) It is permissable to 
have a stop instruction immediately after a 
repeat instruction and it will cause the keyer 
to stop after the second pass through the 
sequence. As an example of how the repeat 
instruction can be used I have the following 
sequence stored in my keyer: CQ CQ CQ DE 
W1GCA W1GCA W1GCA (repeat) K (stop). 
When sent from memory it comes out a 
CQ CQ CQ DE Wl GCA W1GCA WI GCA CQ 
CQ CQ DE W1GCA W1GCA W1GCA K 
(stop). 

The conclusion of this series will discuss 
the sidetone, transmitter keyer, power 
supply and displays. The spare gates indi- 
cated in Figs. 5 and 8 will be used for the 
sidetone and transmitter keyer. 

. . . W3HPX 



96 



73 MAGAZINE 



QSLs 



for 





9 two styles 

• QSO info back 

• two colo rs 

• LOW PR/C£o 



While the 
everything 



. A - Black type 
Style a 

cost of almost 

keeps spiraling 
upward, 73 has kept the 
price of these beautiful 
QSLs at rock-bottom. When 
we started selling Top 
Quality QSLs last year for a 
PENNY-API ECE (postpaid 
yet!) it was a fantastic deal; 
this year it's the next best 
thing to having an oil well Styl efi- Je 

in your own backyard! e BJack °» WhiteT~~~ 

These QSLs are printed on Fine Quality Glossy Card Stock and are 
as good or better than cards sold elsewhere for several times the 
price. We can offer this fantastic low price, because we "gang print" 
orders between other jobs in our own print shop which keeps the 
costs way down and we pass the savings on to you. If you haven't 
been QSLing as much as you'd like to because of the cost of cards, 
do you really have an excuse anymore? Get some cards and help 
improve the image of U.S. Amateurs. 

nnnaannapaDnan order blank npnaanDaannana 




ORDER - AND PAY 



250 . 
500 . 
1000 
2000 



_ . 



- $6 <2.5dea> 
. .$10 [2i ea) 
$15 M.5tf ea) 
. .$20 (1d ea) 



Name 



(First and last name fs most friendly) 



Call 



Address _ 



(as brief as possible and still get through the mail) 




City 



State 



ZIP 



(a must) 



.County, 



(if desired on the card) 



Awards to be listed on card 

□ 250 □ 500 D 1000 D 2000 cards 



Foreign Orders: Add following amounts 
for shipping and handling, (Parcel Post) 



(if desired) 

Amount enclosed $. 



250— $1.75 
500 — $2.25 



1000 — $4,00 
20O0 — *6.25 



Check local Post Office for air rates . 



A product of 73 Magazine, Peterborough NH 



Gary L. Tater W3HUC ex Kl YLU 
7925 Nottingham Way 
EUicott City MD 21 043 



OSCAR 7 



With One Receiver 



After reading the fine technical articles 
on preparing for OSCAR 1, perhaps 

you are wondering how you will use all of 
the OSCAR 7 capabilities without: 

1. Buying a new crystal for your 144 
MHz and 432 MHz converters. 

2. Retuning your receivers 10 meter band 
to include 29.975 MHz and losing 28.0. 

3. Tying up several receivers. 

If you have an NC-300 or NC-303 as a 
spare receiver at your station, here is a 
simple, convenient and inexpensive solution 
that will allow you to use both OSCAR 6, 
OSCAR 7, and the low end of 144 and 432 



MHz bands without adjusting or changing 
crystals in the equipments. 

The downlink signals for the two 
satellites are listed in Table 1, along with 
receiver requirements for 28 MHz i-f VHF 
converters. Very few ham band receivers 
cover frequencies above 29.9; however, the 
NC-300/303 series has a converter band that 
begins at 30.0 MHz. 

Fig. 1, shows an NC-303 configured to 
monitor all three of the OSCAR 7 downlinks 
and beacons using the receiver band switch 
and one external coaxial switch. The only 
modification necessary is to tune the 
capacitor in the NC-303's converter band 
local oscillator such that 29.9 MHz is 
received at the 143.5 MHz (30.0 MHz) dial 
calibration. This should be accomplished 
with the receiver in its cabinet. At this time 
you should also adjust the air trimmer in the 
rf amplifier by using the crystal calibrator as 
a signal source. 

I do recommend the use of a good solid 
state 10 meter preamp as shown in Fig. 1. 
An additional coaxial switch could be used 
to return the converters to the 10 meter 
input for a complete satellite, 432 and 2 
meter station in one receiver. 

. . .W3HUC 



TABLE 1 
OSCAR 6 and OSCAR 7 input, output, beacon and station receiver requirements 



OSCAR 6 
BEACON 



UPLINK 

(MHz) 

145.9-146.0 



DOWNLINK 

(MHz) 

29.450-29.550 
29.450 



RECEIVER 

(28 MHz IF) 

29.450-29.550 
29.450 



OSCAR 7 



BEACONS 



432 MHz 

ANT 



# 



144 MHz 
ANT 

28 MHz 
ANT 





145.850-145:950 
432.125-432.175 



432 MHz 

CONV 



144 MHz 
CONV 



29.40-29,50 

145.975-145.925 

29.5 

145.98 

435.1 

31.1 MHr 



t 



10M 
PREAMP 



29,975 - 29.925 
29.4 - 29.55 



29.40-29.50 

29.975 29,925 

29.50 

29.98 

31.1 



VHF CONVERTER BAND INPUT 



80-10M INPUT 



NC - 300/NC - 303 



Fig. 1. A single receiver for satellite use. 



98 



73 MAGAZINE 



73 Staff 




GH 



OU 




ACCESSORY 




CROPHONE 



B frequently with either an SSB or FM rig 
the built-in microphone amplifier does 
not produce sufficient gain to achieve full 
modulations when used with an existing 
microphone. There are several obvious solu- 
tions to this problem but while either the 
technical or economic aspects are being 
solved, one might consider the use of the 
auxiliary microphone described in this 
article. Its output level is variable and can 
exceed that of a dynamic microphone used 
with a microphone preamplifier. The cost is 
extremely low and yet it has a very good 
speech-engineered response. Needless to 
emphasize, it is extremely rugged and 
durable. 

Before going too far in describing the 
virtues of this microphone, it should be 
pointed out that a carbon type microphone 
is the theme of this article. Before discarding 
the idea because carbon type microphones 
evoke memories of old, noisy, telephone- 
sounding instruments, one should consider 
that even carbon microphone technology has 
advanced in recent years. No suggestion is 
made that one use any of the old war surplus 



type carbon microphones. However, the 
newer telephone type carbon microphone 
elements, and particularly those developed 
for use in private telephone-type intercom 
systems, are definitely good speech quality 
units that proudce a minimum of noise. 
Listen carefully once to a modern telephone 
type unit and the audio quality it provides. 
The particular carbon type element shown in 
this article is an imported type used in 
intercom systems but any of the new re- 
placement types available from microphone 
manufacturers should provide an equal or 
better level of performance. (Fair Radio 
Sales, Lima, Ohio 4582 has a number of 
modern, excellent grade military surplus 
types.) 

Microphone Circuit 

The quality and reliability achieved from 
a carbon type element depends a great deal 
on how it is connected into a single circuit 
which provides a resting current through the 

microphone element. One fact that is im- 
mediately apparent when experimenting 
with modern carbon elements is that ex- 



OCTOBER 1974 



99 



CARBON 

MIC 
ELEMENT 



1/6 V 



-* AUDIO 



Li 



560 



IOO/6V 



2 



GAIN 



/£"{ 



* PTT LINE 



JT~ 



GROUND 



3V 



y 



shielded or 

UNSHIELDED 
CABLE TO 
TRANSMITTER 



J, 



Fig. 1. Complete microphone assembly with gain 
control. 

tremely little current has to flow through 
the microphone to provide a good level of 
output. For instance, the circuit of Fig. 1 
provides a current through the carbon 
element (when the push-to-talk switch is 
activated) which is determined by the 3V 
battery and the series combination of the 
560 fixed and 10K variable resistors. Even 
with full resistance in the circuit, the output 
level is approximately equal to that of a high 
output level dynamic microphone. This rep- 
resents a current of less than 1 mA and was 
one reason, as described later, why the 
batteries for the microphone were placed in 
the microphone enclosure. Under normal 
usage, their life will approach shelf life. The 
lOOjuF bypass capacitor isolates the 56012 
resistor as the terminating af impedance for 

the microphone elements. This resistance 
value can be varied up to several thousand 

ohms if it is found that doing so provides a 
better match or output level when used with 
a particular amplifier. The push-to-talk 
switch simply activates the normal push-to- 
talk line for a transmitter as well as com- 
pleting the battery circuit for the micro- 
phone during transmit. 

Since the microphone circuit is inherently 
a low impedance circuit, one does not 
absolutely have to use shielded cable to the 
transmitter although it is recommended. One 
thing that will be immediately obvious is the 
lack of problems that occur with rf feedback 
when using the microphone. It is quite a 
contrast to the situation that usually occurs 
when one uses a low level output micro- 
phone and an accessory preamplifier ex- 
ternal to a transmitter. 



Construction 

The microphone along with its batteries 
can be enclosed in almost any simple en- 
closure that can accommodate the volume of 
the components. The enclosure need not be 
a metal unit. I simply used a clear plastic 
box (later painted black) which measured 
about 2x3xyi in- and provided a comfortable 
"feel" when hand-held as a microphone 
enclosure, A number of holes were drills in 
the enclosure in a more or less circular 
pattern where the microphone face would 
press against the enclosure, A thin foam 
plastic sheet (or grill cloth) should be placed 
in the enclosure behind the holes toactasa 
moisture and wind screen. 

The mounting of the rest of the com- 
ponents is simply a matter of convenience. 
The only component that one might want to 
check the mounting of carefully is the 
push-to-talk switch. Strangely enough, many 
people who are normally right-handed will 
hold a microphone in their left hand and a 
mounting for the switch in the upper right 
hand portion of the enclosure will prove the 
easiest to use. I used regular AA batteries 
but the current drain is so low, button type 
batteries can be used and the enclosure size 
reduced even further. The 10K variable 
resistor was brought out on the back panel 
of the enclosure with a screwdriver slot shaft 
as a convenience when making tests. 

Summary 

The simple microphone described was not 
intended to replace more expensive dynamic 
units and aside from its high output no claim 
will be advanced that it sounds better than 
an expensive dynamic microphone. However 
on the air tests have shown that it does 
sound as good as inexpensive dynamic units 
intended for speech usage and, of course, far 
superior to cheap tape recorder dynamics for 
speech purposes. The output level can be 
adjusted to at least ten times that provided 
by a dynamic microphone and the whole 
assembly provides an ideal interim solution 
to the problem of working with a transmit- 
ter that requires an unusually high micro- 
phone input level or with FM stations or 
repeaters that require varying deviation 

leVdS * . . . 73 Staff 



100 



73 MAGAZINE 



Cassette Code Courses 

With these Code Courses from 73, the average person can learn the International Morse Code fast enough 
to pass FCC code exams from Novice thru Extra Class in a few painless hours! One of the beauties of 
cassette tapes is that you can take them with you anywhere — at work for lunch break (code on rye is 
great) — even in the car while you are driving (or what's more likely, moldering away in line at a service 
station trying to get gas). With the help of these tapes passing the code portion of the various exams is a 
gas . , . e/~ . . . snap! 



o 



o 



My i' lass was so enthused over your 
code cassette tapes that after hear- 
ing the 13 word per minute cassette 
every student in the class decided 
to get one for home practice. En- 
closed is an order for 23 of the 13 
word per minute tapes, 

K6MLC 

After about a week of playing your 
J 3 word per minute cassette { which 
I timed out at 14 words per minute, 
incidentally?}, I went down and 
passed the General exam with no 
strain. The plain language of the 
FCC exam seemed so slow that I 
lost all fear after the first few, 
letters and made perfect copy from 
then on, It V fear that gets you, and 
your tape gave me confidence. 
Thanks! 

WN9JGQ 



C^/Ve been teaching code for over 
twenty years now and I've tried 
every record and tape and other 
gadget that has come out. Let me 
say that the 13 MAGAZINE code 
course is by far the finest that 1 
have ever heard. I never thought! 
would learn new tricks, hut you've 
taught me a lot about teaching 
code. Suffice it to say, I am recom- 
mending that ev cry s t u de n t of m i ne 
get vour tapes. 

K1IF 



t/Mv r wife, who has been almost 
totally resistant to the code, breez- 
ed through your 5 word per minute 
beginners cassette and was ready 
for the Novice exam in one daw 

WB8JON 



|T1 Bask 5 WPM Code - this 
cassette code course will teach the 
IMC at five words per minute, all 
letters, numbers and punctuation, 
The tape not only gives all these 
characters, but gives them in a very 
simple order so you can start 
copying code with in one minute of 
hearing it. This has got to be the 
easiest way to learn code ever 
invented. The cassette actually has 
the code being sent at 6 WPM , 
allowing a margin for operator 
panic when the chips are down and 
the real exam is at hand. 

Basic Code 5 WPM - 60 min. $3,95 



to stop translating the dits and 
dans, and go to an automatic re- 
cognition system where you 
"know" what the character is with- 
out thinking, thus enabling you to 
pass the general or advanced code 
test. This very nasty tape is really at 
T4 wpm, to give you that added 
edge when taking the exam, 
BB-13 WPM - 60 min. $3,95 



2J 6 WPM Practice Tape - (also 

known as The Back Breaker) this is 
a toughie — five character code 
groups sent in no particular order, 
so there is no way to memorize the 
tape. It is sent at six words per 
minute to give you that margin for 
error you'll need when faced with a 
stern examiner at THE EXAM, 
Practice In your head or on paper 
wherever you are, whenever you 
have a minute or two. 

BB 6 WPM - 60 min. $3.95 



3J13 WPM Practice Tape - This 
tape will take anyone over the 
hump which exists when you have 



2Q WPM Practice Tape - This 
cassette has been fiendishly design- 
ed to get you through the FCC 
Extra Class code test with f tying 
colours. The code on this actually 
runs about 21 words per minute, 
though it starts out at a lazy 18 per 
for the first few minutes. The Inter- 
mix of letters, numbers and punctu- 
ation instead of plain language will 
give you such an edge when you sit 
down to take the exam that you 
should be able to breeze through. 
Though much of your practice with 
this cassette can be just copying in 
your head — after all, the important 
object of practice is to train your 
brain to convert code into letters — 
be sure that you exercise your 
pencil too. The cassette will make 
your code practice portable, avail- 
able to you whenever you have a 
few minutes to spare— even while 
driving. 
BB-20 WPM - 60 min. S3. 95 



Cassette 

Recorder 

Here is a cassette recorder that is 
ideal for use with the code courses 
since it cart be operated anywhere. 

Comes complete with four "D" 
batteries, AC power cord, earphone 
and mike and is useful for dozens 
of ham applications. Cassette tape 
recorder is available for only 
$23.95 (plus S1 .00 for shipping and 
handling). 



Deluxe 

Recorder 

Key operated — and the keys lock 
for easier rewind and fast forward 
operations, which you will appre- 
ciate if you have a recorder that 
doesn't do this — as most don't. 
Record: with mike or from line 
input [telephone, receiver, etc J. 
Has monitor output, AC or built-in 
batteries - comes with batteries 
supplied. Has automatic gain for 
recording so you don't have to 
watch the recording level all the 
time. 

Deluxe Recorder 

$32,95 postpaid in U.S.A. 



Order Today from 73 Magazine 



taster qharggi 



PETERBOROUGH, NH 03458 



BankAmefhcard 



OCTOBER 1974 



101 



Walter VI. Pinner WB4MYL 
7304 Lorenzo Lane 
Louisville KY 40228 



A High Power Low Pass Filter 



The construction of a low pass filter 
capable of handling maximum legal 
power levels is usually complicated by the 
following factors. 

1. Most construction articles describe units 
for 250 watts or less. 

2. Filters for higher power levels require 
special capacitors which are not readily 
available (not to mention cost). 



tors is. This filter is designed for use in 52 
ohm lines, but any standard filter may be 
built by applying the capacitance value of 
the board per square inch and calculating 
the box size accordingly. The capacitance 

of 1.5mm (1/16 M ) double clad board was 
measured at 14 pf per 6,5 sq. cm. Phenolic 
or epoxy measured essentially the same. 
2mm (3/32 in.) board measured 8 pf per 6.5 
sq. cm. 




Fig. 1. Pictorial view of the low pass filter. It is built entirely from double sided copper clad stock, 
with etched out sections of the board serving as capacitors* 



3, The physical size of such capacitors in- 
crease the over-all size of the unit, if var- 
iable, require equipment for alignment 
and usually will not lend themselves to 
following the original layout. 
The filter described herein requires no 
capacitors, double-sided copperclad board 
is used as the capacitive elements. If the 
dimensions are followed NO alignment is 
necessary, and the overall size is 
small 5x5x24.5 cm. 

The materials needed for construction 
are, double clad copper board 1.5mm 
(1/1 6"), #10 solid copper wire and 2 SO 
239 connectors. 

The circuit for this fitter is not new, but 
the use of copper clad board for the capaci- 



A line drawing of the low pass filter is 
shown in Fig. 1. There are four shielded 
compartments, The inside walls of each 
section form one plate of the capacitor with 
the outside of the box forming the other 
plate. 

The box ends, dividers and foil track are 
all at ground potential Fig. 2 shows the 
electrical circuit of the filter. The 

copperclad board parts are all soft soldered 
in place. Fig. 3 is the dimensional drawing of 
the board which makes up two sides of the 
box. The ,3cm (1/8 M ) cm wide insulating 
tracks may be etched or cut using a hobby 
or carpet knife and the foil peeled away. The 
board is then cut in half, the cut ends filed 
to a 45 degree angle and the two halves 



102 



73 MAGAZINE 



LI 



CI 
70 



m 




Fig. 2, Schematic of the filter* AH coils are #10 
copper 1.2cm (W) inside diameter. LI and L5 are 
5T, 2cm (W*) long; L2 and L4 are 6T r 2Acm (1 ") 
long; L3 is 8 l AT, 3,8cm (1 H ") long. 

soldered together being sure to solder both 
the inside and outside surfaces. The method 
of bonding the inner ground track and the 
outer surface together is via a number of 
holes drilled through the board with pins or 
wires passed through and soldered to each 
copper surface. The shields can also be 

made of copper clad with (,6cm) holes bored 
through their centers for coi! connections. 



SOLDER RNS 

X 



CUTS 

TAPER- 

45* 



5 



24 5cm 



3.2 cm 



CI 






6 2cm 



C2 



6 2cm 



C3 



3 2cm 



C4 



GROUND TRACK 




(0.2 cm 



Isolating tracks .3cm (cut or etch). 



Fig, 3. The capacitors are formed by etching 
isolation tracks around sections of foil. 

The cover may simply be light weight 
aluminum bent at a 90 degree angle and 
holes drilled to line up with the mounting 
nuts soldered to the inner ground track. 
Wind the five coils from the table below and 
solder them into the box using Fig. 1 as a 
guide to positioning. Install the cover and 
hook-er up. The filter I constructed worked 
fine when 1200 watts were run through it 
into a 50Q dummy load. No increase in swr 
was noticeable. The frequency cut-off is at 
30 MHz, with the attenuation falling sharply 
to 40 MHz, 







. . . WB4MYL 




COIL TABLE 






No. of Turns 


Length 


L1 & L5 


5 turns 


3/4 in. 1.9cm 


L2& L4 


6 turns 


15/16 in. 2.4cm 


L3 


8% turns 


1 !4 in, 3.8cm 



All coils #10 solid copper wire 1.1cm (7/16) inside 
diameter. 



i- *U 






For 

FREQ. 

STABILITY 

Depend on JAN Crystals. 



Our large stock of quartz 
crystal materials and components assures Fast 
Delivery from us. 

CRYSTAL SPECIALS 

2-METER FM tor most Transceivers ea, S3. 75 
144-148 MHz — 0025 Tol 

Frequency Standards 
100 KHz (HC 13/U) 
1000 KHz (HC 6/U) 

Almost all CB Sets. Tr. or Rec 

(CB Synthesizer Crystal on request) 
Any Amateur Band in FT-243 1.50 

(80-meter, $3,00 — 160-meter not avail.) 4/$5.00 
For 1st class mail, add 20c per crystal. For 
Airmail, add 25c. Send check or money order. 
No dealers, please. 



Division of Bob Whan 

& Son Electronics. Inc 

2400 Crystal Drive 

Ft. Myers Florida 

33901 

All Phones 
(&13) 936-2337 



Send 10c for new catalog with 12 oscillator 
circuits and lists of frequencies m stock 



JOB OPENING FOR PERSON 
WHO CAN READ AND WRITE 

Editorial Assistant for 73 Magazine 

Person should be well read, particularly 
in electronics, and know a nor gate from a 
neutralizing capacitor* While not many 
articles in 73 are re-written, many do need 
attention as far as speling and grammar is 
concerned. Not casting any stones, but we 
don't want 73 to print garbage like you find 
in Brand X magazine. 

Said job pays a lot more than it ought 
to t considering that New Ham Shire is one 
of the very best places in the whole US of A 
to live (ask any Calif ornian who has had the 
good fortune to move to NH!)- No sales tax 
— no income tax - rolling green hills and 
beautiful mountains (for DXing on VHF) - 
incredible 2m territory (would you believe 
eight repeaters on the air in NH and three 
more under construction!). 

The A. Editor prepares articles and 
newspages for publication - editing them, 
making sure the pictures are okay, and 
works with the authors to make sure that 
everything is the best it can be. 

If you are qualified and think you might 
like to join the gang at 73, write and tell 
Wayne about it. 
73 Magazine — Peterborough NH — 03458 



OCTOBER 1974 



103 



mm 



Harry Simpson W4SCF 
PO Box 27015 
Memphis TN 38127 



' WAS 
BENCH 




JOB 



We were scheduled to leave on vaca- 
tion the next week so I took my 
charming red-headed helpmeet, WB4ECK, in 
for her 10,000 mile checkup. The Doc told 
us to run, don't walk across the street to the 
hospital for an operation. Everything came 
out all right (E-e-c-c-k-k!) and while she was 
convalescing, I asked her to tell me all about 
the operation, 

She said, "Well, I'll try to explain in 
terms that you can understand. First, they 
removed the chassis from the cabinet and 
placed it on the bench. A visual inspection 
followed, and certain parts were suspect. 
This called for a closer examination of the 
various components. 

A scope was hooked up, as was a spec* 
trum analyzer and a VTVM. The master 
oscillator was checked for distortion — 
fortunately none was found. However, the 
VTVM showed a higher supply voltage than 
that outlined on the spec sheet, and a 
procedure was outlined for reducing that 
potential in the future. 

The main difficulty was discovered in the 
harmonic generator, and after a conference 
with the shop foreman it was determined 
that this unit was beyond repair - and at the 
same time was of no importance to the 
overall operation, in relation to its current 
use. It was also decided that the parts 
making up this generator could continue 
their deterioration and damage the entire 
assembly if not completely removed -just 
as you remove dead batteries from a VOM! 



After allowing an overnight cooling off 
period, the bench crew got down to work 
early the next morning while everyone was 
fresh, and began the conversion. In order to 
keep down extraneous noise — there was 
nothing wrong with the audio amplifier — 
they reduced the power to a very low level, 
and started to work. With all the test 
instruments hooked up, they cut a long slot 
in the shielding which enclosed the defective 
generator, and using diagonals and long- 
noses, very efficiently removed the trouble- 
some components, and then placed jumpers 
in certain locations to insure proper future 
operation. 

Following a careful visual inspection to 
assure themselves that they had left no tools 
inside the compartment, they carefully re- 
placed the shielding, and sealed it with a 
slow-hardening type of epoxy. Then they 
gently raised the operating voltage back up 
to normal. Fortunately, everything worked, 
and the chassis was moved to a cool, quiet 
spot to wait for the epoxy to set f 

Attached to the repair bill were instruc- 
tions to cushion the device, thus protecting 
it from mechanical shock, vibration and 
bouncing, and to let it run on idling current 
at first, then gradually increasing the duty 
cycle, until finally the rated output is 
reached." 

W4SCF: "Chee-well, if they didn't 
leave any cold solder joints at least you 
don't have to be bothered with harmonic 
filters . . ." 

. . .W4SCF 



104 



73 MAGAZINE 



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IheBookl 



NOVICE CLASS 
STUDY GUIDE 

$4 

The world's easiest to understand 
book on the theory required for the 
Novice amateur radio license exam* 
Frustrated by fundamentals? Read 
this book. One simple reading should 
carry you through the exam. 

GENERAL CLASS 
STUDY GUIDE 

$6 

This book will help you to really 
understand the theory and enable 
you to easily pass the FCC exam, 
This is not a Q&A manual for 
memorization. Study this book and 
go into the exam with confidence* 

ADVANCED CLASS 
STUDY GUIDE 

$4 

Thousands have used this book to 
help them breeze through the 
Advanced exam with no strain. This 
is the ONLY study guide published 
which covers ALL the material you 
will have to know* 

EXTRA CLASS 
STUDY GUIDE 

$7 

Does the theory required for the 



Extra Class exam pan?c you? No 
need, for this book reduces it to easy 
comprehension. Many amateurs find 
that a quick reading through this 
book is enough to get them through 
the tough Extra Class exam- Face 
that exam with confidence. 

1974 
FM REPEATER ATLAS 

$1.50 

Listings by states (or countries) and 
cities of all repeaters, both open and 
closed, in the world. Periodically 
updated. Handy size for mobile use. 

FM REPEATER 
CIRCUITS MANUAL 

hardbound $7 
softbound $5 

Contains almost every conceivable 
circuit that might be needed for use 
with a repeater. All circuits explained 
in detail. All aspects covered, from 
the operator to the antenna. Also 
contains chapters on setting up a 
mobile station, plus much more. 

HOW TO USE FM 

$1.50 

This book presents the basics of 
two meter FM operation and re- 
peaters in short farm with the end in 
mind of getting you on FM quickly 
and easily. 

It is easy to make some blunders 
when you are getting started with 

anything new. It is also embarrasing. 
A fast reading of this book should 
help you avoid the pitfalls* 



VHF PROJECTS FOR 
AMATEUR AND EXPERIMENTER 

$5 

A must for the VHF op. Opening 
chapters on operating practices and 
getting started in VHF, both AM and 
FM, followed by 58 chapters on 
building useful test equipment, 
modifying existing and surplus gear, 
building complete stations, both 
fixed and portable, Hnears, conver- 
ters, control units, preamps, band 
scanners, antennas, noise suppression, 
plus many more. 

FASCINATING WORLD OF 
RADIO COMMUNICATIONS 

$4 

All about broadcast band DXing, 
tuning the tropical DX bands, DXing 
radio amateurs, antennas for short- 
wave, radio licenses, pioneers in elec- 
tricity and radio, commercial broad- 
cast stations, WWV, etc, 

TVI 

$1,50 

Discusses all types of interference 
problems in great detail with recom- 
mended steps to cure these problems. 
Good for both the amateur and 
citizens band operator. Try this cure 
and suffer no longer. 



IC PROJECTS 



$4 



This book tells how to understand 
and use ICs, with number ous con- 
struction projects. 



COAX HANDBOOK 

$3 

All about coaxial cables, connectors 
and applications. It's all here — pic- 
tures, part numbers and specifica- 
tions for all types. 

SOLID STATE 
PROJECTS 

$4 

More than 60 projects of interest to 
anyone 1 in electronics. The devices 
range from a simple transistor tester 
to a ham TV receiver* This collection 
will help you become more 
intimately acquainted with xeners, 
ICs and varactors, etc, 

TRANSISTOR PROJECTS 

*3 

Crammed full of home construction 
projects, from receivers to trans- 
mitters and all in between. Chapters 
include such articles as zener diodes, 
how they work, how to use, test and 
buy them; integrated circuits; how to 
design transistor amplifiers; and 
many more. 



DX HANDBOOK 
with MAP 

$3 

How to work DX, how to get 
QSL'S, country lists, award lists, QSL 
bureaus, maps of the world, great 
circle maps centered on major U.S. 
cities, DX bearing charts for major 
U.S. cities, how to go on your own 
DXpedition, and much more. Wall 
si/.e DX map of the world included. 






3 






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more Bookl 




DIODE CIRCUITS 
HANDBOOK 



INTRODUCTION TO 
RTTY 

$2 

In this book the world of radio- 
teletype is explained in an easily 
understood manner for the beginner. 
There's also a chapter on RTTY Art 
which will teach you everything you 
need to know in order to be a RTTY 
Artist, The last part of this book 
contains a bibliography of everything 
published about RTTY since 1952* 



RTTY HANDBOOK 

$6 

A comprehensive book covering all 
areas of radio teletype, from getting 
started with the basic principles, 
what equipment to procure and how 
to make it work. The only up-to-date 
book available on the subject. Well 
written, easy to read and understand. 



73 USEFUL 
TRANSISTOR CIRCUITS 

$1 

Useful transistor circuits for audio, 
receivers, transmitters and test equip- 
ment. 47 chapters with circuit dia- 
grams for each, complete with com- 
ponent values, etc. A must for the 
solid state home brewer. Easy to read 
and to understand* 



SLOW SCAN 
TELEVISION HANDBOOK 

hardbound $7 
sof tbound $5 

This excellent book tells all about 
it, from its history and basics to the 
present state-of-the-art techniques. 
Contains chapters on circuits, 
monitors, cameras, color SSTV, test 
equipment and much more. 

i 



$1 



115 diode circuits including power 
supply application, regulators, ac 
meter applications, receiver detectors 
for AM-FM-SSB, noise limiters, 
squelch, AGC, varicap tuning, audio 
clippers, compressors FM modula- 
tors, RTTY keying, varactor multi- 
pliers, noise generators, 

VHF ANTENNA 
HANDBOOK 

$3 

Would you believe that the secret 
to success in VHFyUHF is in the 
antenna system? This is no earth 
shaking discovery, but it's true. A 
complete, detailed book with descrip- 
tions, dimensions, tuning data, dia- 
grams and photos. Antennas from the 
instant coathanger to the giant 
collinear beam can be found here. 

DIGITAL CONTROL 
OF REPEATERS 

hardbound $7 
sof tbound $5 

Here's a book for the FMer who 
wants to design and build a digital 
repeater control system. Contains 
sections on repeaters, basic logic 
functions, logic circuit design, con- 
trol systems, support circuits, mobile 
installations, touch-tone, plus a 
special section on a "mini** repeater 
control system. 



CONVERTING COMMERCIAL 

FM GEAR 

$2 

General information on commercial 
FM gear with specific conversions for 
Motorola equipment. 



the fluff 





the Stuff 



73 CERTIFICATES 

WAAS $1 

Worked Almost All States — Proof 
of your having worked 49 of the 50 
states. It is for those who are just 
unable to get that last state 
confirmed. 

RRCC $1 

This Real Rag Chewers certificate is 
awarded only for the feat of a non- 
stop QSO for a period exceeding six 
hours with no time out for anything. 
Order must be accompanied with 
date/time (GMT) of start/end of con- 
tact, station contacted, and your call 
sign. 

DXDC $1 

Available for those who present 
proof of contact (copy of log) with 
10 different countries. Awarding this 
certificate makes you a member of 
the DX Decade Club. 

RTTY-DXDC $1 

Frame and hang this one above 
your machine. All operating award 
for those who have submitted proof 
of 2-way teletype communications 
with 10 countries. Endorsement 
provisions for different bands. 

SSTV-DXCC $1 

Dress up the shack with this award 
for 2-way Slow Scan Television com- 
mit ni cations with 10 countries. 
Endorsement provisions for separate 
bands. 

ALL MODE DXDC $1 

How many can qualify for this one? 
An award for 2-way communications 
with 10 countries using 
CW-SSB-RTTY-SSTV modes. 



UNDERSTANDING, XYL/OM $1 

An unusual certificate — get one 
and keep your mate happy. An award 
to those who have the good fortune 
of having an understanding partner 
who appreciates all good things about 
amateur radio (staying up all night, 
spending money for rigs, etc). 



CHC 



$1 



Presented to those who submit a 
sworn statement that they have never 
received a certificate for radio operat- 
ing and if they ever receive one, they 
will hate it. This certificate should be 
your first before you accidentally do 
something and receive a certificate 
for it. This attests to your 
membership in the Certificate Haters 
Club, 



sufficient 
of your 



Be certain to enclose 
postage for the return 
QSLs, 

73 BACK ISSUES 



VOLJ $4 

This is an assortment of twelve 
different back issues of 73 from the 
years 1960 through 1964, Normally 
these back issues would cost you $1 
or more each, but since this assort- 
ment is our choice instead of yours 
you benefit with a big bargain. Here 
is a good way to build up your 
technical library with hundreds of 
interesting and valuable technical 
articles and construction projects, 

VOL. 2 $4 

Twelve different back issues of 73 
from the years 1965 through 1967. 
These are the real vintage years of 73 
for home builders of transistorized 
gear. Lots of VHF projects and 
gadgets galore* See for yourself what 
73 was doing back when QST was 



more Muff 




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<D 

%J 




O 
*4 



the Muff 

(continued) 



still bringing you only tubes. At this 
price you get oui choice of back 
issues- This is an excellent way to fill" 
in missing back issues, if you like to 
gamble. 

VOL. a $4 

Twelve different back issues of 73 
from the years 1968 to 1972. These 
bundles are already made up so you 
have to accept our choice at this 
price, Individual issues for most 
months are still available for $1 each 
for these years, 

MAGNETIC CALL SIGNS 

$4 

Let the world know that you are 
proud of your ham call. These 
magnetic call signs will adhere to the 
side of your car, and they won't fall 
off at high speeds. 

U.S. MAPS 

$1 

These wall sized maps show the 
states and call area. They are 
specially designed for coloring to 
show your progress toward the Work- 
ed All States award of ARRL or the 
Worked Almost All States award put 
out by 73 (for proof of contact with 
49 states). Since you will probably be 
wanting to work for the award on 
several bands you will want several 
maps. They come in groups of four, 

WORLD DX MAP 

$2 

This is the same wall -sized DX map 
that is included with the DX Hand- 
book except it comes to you rolled 
up instead of folded. This is so you 
can put it on the wall or have it 
framed. The map is designed with all 
country prefixes indicated and space 
for you to color in the countries as 



you work them. Visitors can see 
immediately how much of the world 
you have contacted! The zones are 
on the map as well as prefixes. Maybe 
you need several maps. 



$4 



CUSTOMIZED DX 
BEARING CHART 



An amateur who works for a 
computer company has a program 
which permits him to plug in your 
location and have it print out the 
bearings of all the countries of the 
world from your shack. Once you 
have this list you will use it for every 
DX contact. The chart gives the 
bearing and distance to all major 
cities and countries. Be patient when 
you order for these have to be run 
through in groups so that we can 
offer them to you at such a low cost. 

73 BINDERS 

$5 

These binders are a gorgeous red 
and come with the nicest set of year 
stickers youVe ever seen. The perfect 
thing for storing your issues of 73 so 
that they won't get lost or spilt on, 
or into the hands of the Jr. Op. Dress 
up your shack with these binders. 

LAPEL BADGES 

$1 

Name and call identifies you at club 
meetings, ha infests, busted pot 
parties. Hand engraved by skilled 
New Hampshire craftsman with lov- 
ing care. Only one lousy dollar. Send 
first name and call. 

CALL LETTER 
DESK PLATE 

$2 

How about dressing up your operat- 
ing table with a desk plate showing 
your first name and call? These em- 
bossed desk plates are nice — and 
inexpensive. No zero available, sorry. 
There is room for twenty letters and 
spaces total. 




Gabriel F. Cargiulo WA1GFJ 

17 Whitney Street 

East Hartford CT 06618 



HAM 



RADIO 



AND 




GN 



LANGUAG 




We hams have a rare privilege. By 
picking up a microphone we can 
talk with people almost anywhere in the 
world. Few can afford to travel abroad, but 
we can ail afford to visit in the living rooms 
of foreign hams by the magic of amateur 
radio. 

What we say on the air can make some- 
one's day a bit happier or it can make it a 
disappointment. What goes out through our 
antennas can affect what many people think 
of America, 

Most Europeans think that Americans are 
loud, rude, free-spending, and ignorant of 
any language other than English. 

Those of us fortunate enough to enjoy 
ham radio can do a lot to create a good 
impression of our country. We can learn the 
other fellow's language and talk to him in it. 

By learning someone else's language we 
take the first step in opening our mind to 
him, and in communicating with him. A 
language is not just a way of saying things. It 



represents a person's whole culture, his 
heritage, his way of thinking, even his 
religion. When you learn and use his lan- 
guage you are saying: "Your way of life, 
your culture, your values are important to 
me. I want to be closer to you/* 

English is not the only language in the 
world. It happens to be the dominant one 
only because the United States is a dominant 
world power, and because Americans and 
British refuse to learn other languages, Eng- 
lish is dominant on the ham bands because 
most hams are Americans, and they will not 
learn a foreign language. 

If you decide to learn a foreign language, 
here are a few pointers: 

1. Choose a language. It may be one you 
had in high school, or the language your 
grandparents spoke. Try to pick one you are 
likely to hear on the ham bands, such as 
Spanish, French, German and Italian, 
Choose one you can learn easily. There are 
many materials available for learning 



108 



73 MAGAZINE 




5Sd per 



REASONS TO SUBSCRIBE: 
One Year Sub Saves 

DA one year subscription is only $7 
issue. That's a 42% savings. (Egad!) 

Two Year Sub Really Rips Us Off 

DA two year subscription for $12 saves you 
50% — each issue costs only 50<1 (We must 
be nuts!) 

Don't Read This Paragraph 

DA three year subscription takes us for a 

bundle. It's only 

42d an issue — a 

savings of 68%, 

{We certainly 

won't make much 

money off you. 

Come to think of 

it, what kind of person are you, reading this 

paragraph and thinking of subscribing for 

three years?) 

OUR RATES ARE REASONABLE 

□We have managed to hold our subscription 
rates at a reasonable level despite a host of 
rising costs: postage rates (our nemesis, due 
to go up again), staff salaries {itinerant apple 
pickers are making more every year and the 
chimpanzees are asking for more and more 
bananas), rising printing costs and increased 
costs in just about everything else. 




WHAT WE GIVE YOU: 

□ More articles on every facet of amateur 
radio than any other publication. 

□We're usually a couple of steps ahead of 
our competitors in publishing articles you 
want to read about, 

□ More ads than any other Ham magazine— 
that means you can keep up on what's new 
in your hobby. 

□ NEWS PAGES: Read about how hams are 
aiding people during times of crisis. Read 
our special inter- 

est col umns 
which will keep 
you up on what's 
new in your facet 
of ham radio — 
contests — SSTV 

— 50 MHz — Solid State — and more, more, 

more! 

□ An open forum for you in our letters to 
the editor column. Here you can sound off 
on your likes and dislikes {about us or 
anyone else). We publish both sides, 

□ Wayne's Editorials — never boring, some- 
times controversial. They're a great conver- 
sation starter at ham clubs and on the air, 

□ I RS Report: Does an average ham pay 
more in taxes than a mufti-million dollar 
company? Find out how the I RS is out to 
screw you and what you can do about it. 




tow 




DDDnaDnDannnDDDnDnDnnnDn n □ ddd d dddoddddd 



a 
a 
a 
a 
a 
a 
a 
a 
a 
a 
a 
a 



NAME 



CALL 



ADDRESS 
CITY 



STATE 



ZIP 



D 

a 

D 

a 

a 

a 
a 
a 

D 

a 

a 

a 

□□□anQoaaQoaDDDDaaDDDaDnnonDDOonannnnn 

73 MAGAZINE INC. Peterborough, New Hampshire 03458 



LJ Sign me up for a money-saving 1-year subscription for $7. 

□ Here's my $12 to rip you off for a 2-year subscription. 

O YEAH! I'm mean enough to sign up for a 3-year subscription for $15. 
nBankAmericRrd |~) Master Charge Account No .Expires 

|~~j New Subscription [~~1 Renewal 

□ Bill Me Signature 



OCTOBER 1974 



109 



Spanish, French and Italian, but few for 
learning Albanian or Flemish, The best 
choices seem to be Spanish, French, German 
or Italian, 

2. Then learn a little. Get hold of tape 
recorded QSO's (advertised in ham publica- 
tions), language records, (Dover Publication, 
New York) or take a course at any one of 
many language schools ready and waiting for 

you* 

3. Use what you know. You can always 
fall back on English. But remember, English 
is a foreign language for the other fellow. 
Why should he speak your language and not 
you his? 

4. Don't be a perfectionist- Unless you 
can live in the country more than three or 
four years, you will probably never speak 
the language like a native. So speak as 
correctly as you know how, but speak to be 
understood. 

5. Ask your contact for help. Few will 
refuse to coach someone making the effort 
to learn their language. 

In just a few month's time you'll have 
learned to speak a foreign language, ad- 



NEW FOR 74 

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FM Schematic Digest 

A COLLECTION OF 

MOTOROLA SCHEMATICS 
Alignment, Crystal, and Technical Notes 

covering 1947-1960 

136 pages 11 VTx 17" ppd $6.50 

S. Wolf 
Box 535 
Lexington, MA 02173 



vanced international relations, and added 
many hours of enjoyment and warmth to 
your hamming. What language will you 

learn? 

, ..WA1GFJ 

Editor's comments: 

The most difficult part of speaking a 
foreign language is getting started. It can be 
frightening - like learning to ^alk. You feel 
insecure and embarrassed. 

I suggest that you get started slowly and 
easily in the first stages. If you start out by 
learning some of the basic ham contact info 
in the foreign language, and then get so you 
can give more and more of that, you will be 
on your way. After all, if you've worked 
many Italian stations you may have dis- 
covered that a lot of them don't seem to 
know any English at all, yet are able to give 
you the regular ham contact routine in 
English, As long as you stick to the name, 
town, and signal report you are okay. Take a 
page from their book for starters. 

Eh bien w mon ami? Pardon, sll vous plait, 
ma is nous desirons parler en Fran cats pour 
un moment 



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ANNOUNCES 
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DESIGNED FOR THE ELECTRONIC/COMPUTER HOBBYIST' 
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Wnte or phone for departed literature. 

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125 Edgefield Avenue 

Milford, Connecticut 06460 

Phone (203) 874-1573 



WORLD QSL BUREAU 

1200 Panama Ave., Richmond CA USA 94804| 

THE ONLY QSL BUREAU to handle all of 
your QSLs to anywhere; next door, the next 
state, the next county, the whole world. 
Just bundle them up (please arrange alpha- 
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Dynamic Electronics, Inc. - — 

Box 1131 Deejfur.AL 35601 



110 



73 MAGAZINE 



E.R. Davisson K9VXL 
83 Crestview Drive 
Greenwood IN 46142 



SIMPLE SIX 



PRE-AMP 



An easily built pre-amp that will increase the sensitivity of a 
low priced receiver without the necessity of complicated 
imp e dance ma t c h ing. 



Ever wish you could add just a little 
more oomph to that six meter station 

on receive? Well, how about a low cost, 
simple, preamplifier which requires very 
little work? Although only one transistor is 
utilized, this little pre amp has outperformed 
some one and even two tube preamplifiers 
costing many times more. The main consid- 
eration here is that you don't have to get 
fancy and expensive to add a little zip to 
your six meter receiving set-up. 

Figure 1 is the schematic of the unit. At 
first glance, it appears as any other straight 
forward amplifier, However, several things 
were done to increase its overall effec- 
tiveness. 

Notice the output circuit. Utilization of 
the commercial choke produces one big 
benefit. Due to lower Q than would be 
obtained with an air wound coil, no tuning is 
necessary. The bandwidth at the half power 
points will be approximately 10 MHz. In 
other words, you'll notice very little dif- 
ference in gain across the entire six meter 
band. Tuning of the output circuit is ac- 
complished by the 6 pF capacitor. By using 
50 pF in series with the 6 pF across the tank 



coil, the equivalent capacity across the coil 
tunes the circuit to the six meter band. By 
taking the output from across the 50 pF, 
gives an impedance of approximately 50^2 
for matching purposes. 



2N502 



470 PF 



INPUT 



luH 

choke; 



001 




fT7 



£3> 



OUTPUT 



50 
PF 



6.8 uH 
(MO) 



Fig, I, Schematic diagram for simple six pre~amp t 

Don't be fooled by the lack of an input 
tank. Use of the fairly large coupling capaci- 
tor and no tank circuit eliminates the prob- 
lems of detuning often caused by different 
lengths of coax. 

Where this pre-amp shines is with re- 
ceivers of tube input (especially those with- 
out an rf stage). Typical performance of this 
little pre-amp with one well known receiver 
produced the following results. The noise 



OCTOBER 1974 



111 




NOVICE 

CLASS STUDY 

GUIDE 



Much more than a Q&A Manual. With 
thii new book you LEARN the 
THEORY, So simply explained that any- 
one can understand it the first time 
through. Never has there been such a 
simple theory course. Be ready for that 
1974 FCC Exam with this 1974 book. 

Other study manuals ask you to 
memorize questions and answers — this 
one lets you learn the theory so • • * 




you'll know the ANSWERS 

1974 

EDITION . . . $4.95 



Magazine - Peterborough NH — 03458 



KITS 




Sub-Audible tone 
Decoder $9.95 




Encoder $8.95 



Compatible vwth all sub-audible tone systems such ab 
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Glass epoxy PCB's 8t silicon KStrs throughout. 

Any reeds, except special dual coil types may lie used 
Motorola, G,E., RCA # S.D.L., Brarnco, etc. 

All are powered by 12 vbc. 

Use on any tone frequency 67 H? to 250 Hz 

Small size 1.5 x 4 x .75" 

AN parts included except reed vnd reed socket 

Postpaid - Calif, residents add 5% sales tax 

COMMUNICATIONS SPECIALISTS 

P.O. Box 153 Brea CA 92621 




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isolated Pad - Drill ■ Mill 

Precision circuit board construction 
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56.95 ea. 
Calif, residents add 5%, 

A F STAHLER Co 

PO BOX 354 CUPERTINO. CALIF 95014 





level increased one S unit, whereas the signal 
level was increased three S units. The per- 
formance is better due to the inherently 
lower noise figure of transistors compared to 
tubes. 

Do you have a super regenerative receiver 
on six?This little pre-amp ahead of it can 
really make a difference in performance as 
well as cutting down on the radiation com- 
mon to that type of receiver. 

With the 2N502 specified, typical power 
gains between 15 and 20 dB have been 
measured. Drain from a 9 volt source runs 
less than 50 milliwatts. 

One word of caution: make sure the 
input is separated from the output when you 
build up this little pre-amp. Several were 
built (not by me) where this was not the 
case. What you'll end up with is a preamp 
for six as well as a converter (but, who 
knows for what band). 

The choke in the supply lead may or may 
not be necessary. In some applications it was 
necessary to use the choke. 

To increase its effectiveness, try raising or 
lowering the voltage a little* YouTl find a 
point where the best ratio between noise and 
signal level may be reached. 

For the more ambitious builder, we might 
offer the following suggestion. One version 
of this pre-amp was built where commercial 
chokes were switched giving us coverage for 
6, 10, 15, and 20 meters. We used a string of 
live commercial 1 fiH chokes. The band- 
width for the lower frequencies will cor- 
respondingly decrease. This, of course, helps 
due to the decreasing frequency spectrum 
you are interested in. 

If you're really daring, build two, and use 
them in series. Be careful here though, as 
lead dress, component placement, etc., all 
become about ten times more important. 

So, next time you wish for a just a little 
more oomph on six, give this extremely 
simple circuit a try. 

Incidentally, 14 turns of number 22 wire, 
3/8 inch diameter, air wound can be used for 
the 1 juH choke at a sacrifice of bandwidth. 



K9VXL 



112 



73 MAGAZINE 



Paul Schuett WA6CPP/WA7PE! 

Box 10 

Wallace CA 95254 



THE THR 



-WIRE DIPOLE 



After having been on the air a year or 
so, I ran into an old timer who was 

running a 3-wire dipole. I was running an 
ordinary dipole on 40m and a folded dipole 
on 75m, but had given no thought to a 
3-wire dipole. He mentioned that it was a 
good antenna; I thought it would be an 
interesting try. So, one spring day, with 
nothing much better to do, I solicited the 
aid of the jr. Op. and we commenced the 
3-wire dipole. 

First you need some spacers. About this 
time I ran across someone connected with an 
advertising sign company, and he gave me 
some scrap plastic. A moment with a band 
saw and a drill gave the necessary spacers, A 
few minutes perusing the antenna hand- 
books gave me information on impedance 
stepup vs, wire size and spacing. For simpli- 
city, we used the center wire as double the 
diameter of the outer two conductors, mak- 
ing the impedance independent of spacing, 
and giving us a nominal 600O feed point 

Using 75H coax Into a 4:1 balun gives us 
only 3O0H, so a Y*k section of about 45 Oft 
line (slopped together in a hurry using 
approximate measurements) acted as an im- 
pedance transformer. 

This antenna was constructed for 20m so 
that the matching section wouldn't have to 
be too long and because we had about that 
much physical room available between the 
supports. Only one afternoon's work, and up 
it went! This antenna stayed in service about 
a year and gave excellent results. At times, 
depending on conditions, it was possible to 
make contacts impossible to hear on the 
beam. The nicest feature was the extremely 
good bandwidth it was possible to cover 
the entire 20m phone band without the 




ANY REASONABLE EQUAL 
SPACING BETWEEN 
CONDUCTORS 



CENTER CONDUCTOR = 
DOUBLE DIAMETER OF 
OUTSIDE CONDUCTORS 



€00 n 
BALANCED FEED 



SWR going over 1.5:1. No adjustment of 
tuning or loading was necessary once the rig 
was tuned near the center of the band. 

Changes always get made, and this an- 
tenna is now rolled up and somewhere in the 
corner of the garage. The results were most 
gratifying, and I am now building another 
system using two of these in a phased array. 

The advantages of the 3-wire dipole over 
the ordinary dipole are added band wid til 
without impedance change, belter perfor- 
mance in not having to compensate tuning 
or bading when QSYing, and apparently 
some improvement in signal strength. It was 
suggested that since there is more wire in the 
air, there is more capture of received signals 
and correspondingly greater strength in the 
receiver. The same would appear to be true 
on transmit. 

The disadvantages are the higher feed 
point impedance, making it necessary to do 
some sort of matching, the added weight 
with more wire and spacers, and somewhat 
greater wind resistance. 

The advantages and performance out- 
weighed the disadvantages in this installation 
— in addition to many stateside contacts, it 
was possible to work Alaska like they were 
down the street, Siberia, Europe and Latin 
America. 

When you want to spend an afternoon on 
a project, remember the 3-wire dipole. 

. . < WA6CPP/WA7PEI 



OCTOBER 1974 



113 



E. M. Wagner G3BID 
5 Femcroft Avenue 
Lon don N t W. 3 
England 



LOADING 




D 



FOR 





A NOD 



NT OR RF OUTPUT 



Before and shortly after World War II, 
most rigs were home brew and oper- 
ated CW or AM. These rigs usually consisted 
of a series of separate pieces of appartus: a 
transmitter, a receiver, an antenna change 
over relay, a control panel, a send /receive 
switch, and usually an antenna ammeter. 

In those days one often looked at the 
antenna ammeter when loading up. It was, 
of course, clear that the antenna ammeter 
was only a comparative indication, and that 
if any change was made between the antenna 
ammeter and the antenna itself, such as the 
installation of an antenna tuning unit, this 
would materially change the reading on the 
antenna ammeter. 

So, many of us gradually lost interest in 
the antenna ammeter, and in many installa- 
tions it disappeared completely. 

Tuning up was then done by observing 
the final anode current meter. The rig was 
loaded up to a specific anode current. This 
was true when many of us had our antennas 
link-coupled to the tank circuit. 

The anode current meter continued to be 
the most important indication in loading up 
the final when we went over to pi-output 
circuits and for some time the anode milli- 
am meter was the only means of loading up 
the final in commercially built rigs. 

Some people used field strength meters to 



check their loading. Then came some watt- 
meters which could be left in circuit during 
operation. Also several manufacturers such 
as Drake and Swan included comparative rf 
output meters. 

Comparing the loading by the reference 
to the rf output meter with loading by the 
anode current meter, shows clearly that 
these two methods are not always the same. 
If all rigs "looked into" an entirely non 
reactive load of 5012 the difference might 
not exist. But in practice, especially with 
mobile antennas, it is rarely possible to make 
the antenna show a non reactive load of 50 £2 
at all frequencies in the amateur bands. 

Many amateurs still tune up for optimum 
loading (within the prescribed limits, of 
course) of the anode miliiammeter. 

Tests which I have made with several 
different types of transmitters and trans- 
ceivers, including KW Victory, Drake TR3 
and TR4, all show that loading up by 
reference to the rf output gives far better 
results. Often a noticeably lower anode 
current can produce a greater rf output 
indication and reports from the distant 
stations indicate that this is the better signal 
and not the signal obtained by the best 
loading according to the anode current 
meter, 

. * . G3BID 



114 



73 MAGAZINE 



Earle H. Eaton 

851 Springfield Ave. 8D 

Summit N J 07901 



A Digital Interlaced Sync Generator 

for Closed Circuit TV 



Unlike the usual interlaced sync genera- 
tors which employ multivibrator, 
blocking oscillator, or unijunction stairstep 
divider circuits, this digital design provides 
stable operation at low cost, and with few 
components. Only the master oscillator fre- 
quency and output pulse periods need be 
adjusted. The total cost should not exceed 
$20 

Circuit Operation 

Integrated circuit IC-1 is an astable multi- 
vibrator which operates as a 3.5 kHz master 
oscillator. IC-2 through IC-4 are moduIo-N 
dividers which divide the master oscillator 
frequency by 525, producing 60 Hz verticaj 
sync pulses. IC-6A permits adjustment of the 
vertical sync pulse period. 

IC-5 is a modulo-N divider which halves 
the master oscillator frequency producing 
15,75 kHz horizontal sync pulses. IC-6B 
permits adjustment of the horizontal sync 
pulse period. Note that both positive and 



negative pulses are available at the outputs 
of IC-6. 

Adjustments 

Before applying power to the circuit, 
adjust resistors Rl, R3, and R4 for their 
approximate mid -position setting. Apply 
power and check pin 6 of IC-1 with a scope. 
Adjust Rl for a square wave with a total 
period of 32 microseconds. (Since R2 is a 
fixed resistor, the positive and negative 
excursions of the square wave may be 
slightly asymmetrical.) 

Connect a scope to pin 6 of IC-6A and 
adjust R3 for the desired pulse period ( 1300 
microseconds standard). 

Finally, connect the scope to pin 10 of 
IC-6B, and adjust R4 for the desired pulse 
period (7 microseconds standard). This com- 
pletes the generator adjustments. Any slight 
drift of the master oscillator will have little 
effect on the interlace. 

, - .Eaton 



-31.5 KHZ MASTER OSC^ 
Rl 



c 




% 



I - 

2- 
3- 
4- 
5- 

6- 
7- 
6^ 



H6 

-15 

-14 

-13 

-12 

-II 

-10 

-9 



IC PIN CONFIG. 
TOP VIEW 



8 



fe ILL 



12 IC2 
8520 







M 



m 






10 
5 



162 46 7 3 



* 1C3 

6520 



r 



8 



1 



US 



14 9 II 

IC5 
8520 

1624673 
J 11 I I L 




% 



]|4 M 



Js 



IC4 
8520 




It 



u 16 



t 



? 



6 



IC6-B 
1/2 9602 



P0 





> MEG. 




15.75 KHZ 
HORSTNC 




K IC6-A 
1/2 9602 



NEG< 



-% 



P0S 



60 HZ /X\ 

VERT\i/ 
SYNC T 



Fig, L Schematic of the digital interlaced sync generator, R2 is 5.6K l&W 5%; potentiometers are 
miniature and capacitors are mylar, IC-1 and 6 f 960 2PC, are available from Schweber Electronics, 
Syosset NY, $3.00 each plus postage. IC-2 through 5, DM8520, are available from JTM Associates, 
P.O. Box 843, Manchester MO 63011, $L90 each plus postage or from Babylon Electronics, P.O. 

Box J, Carmichael CA 95608, $2.00 each plus postage. 






OCTOBER 1974 



115 



Walter C. Powis K3SCW/AFA3SCW 
239 N. Hammonds Ferry Road 
Lin thicum Heigh tsMD 21090 




On 
Converting 



AC/DC 



The 



For 



WWV 



y the addition of a few simple parts, 

the receiver in the article , "Converting 

the AC/DC for WWV" by W3JJU, Oct 
1971, 73 can be made selectable from 10 
MHz to 1 5 MHz. All of the coil dimensions 
remain the same as in the original article and 
the rf and oscillator sections are retuned by 
switching tuning capacitors. From the circuit 
in Fig. 1, it can be seen that some of the 
parts values have been changed. Capacitor 
C5 is a small variable with its shaft brought 
out to the front panel, This is used to 
compensate for any oscillator drift that may 
be encountered during warmup. During cali- 
bration, this capacitor should be in the 



1ST l-F 

455 KHi 



;2BE6 



ANT 




GROUNDING POINT 



center of its rotation. It should be noted 
that the 15 MHz position has to be cali- 
brated first with C6 to tune the oscillator, 
and C3 to peak the rf amplifier. Then switch 
SI to the 10 MHz position and tune C4 and 
C2 respectively. 

Because of the propagation changes dur- 
ing the day, it is an asset to be able to 
receive more than one WWV transmitting 
frequency. Since l work the 20 meter band 
most of the time, I can usually tell how 
propagation will be by listening to WWV on 
15 MHz, With a little more thought, other 
WWV frequencies can be selected. It is even 
thought that if the cost could be tolerated, 
the oscillator section could be crystal con- 
trolled* 



Parts List 

CT 50 pF silver mica capacitor. 

C2 1.5—10 pF compression trimmer capacitor, 

ELMENCO402 

C3 f C6 7-60 pF compression trimmer capacitor, 

ELMENCO404 

C4 7—100 pF compression trimmer capacitor, 

ELMENC0 423 

C5 1.8—8.7 pF miniature variable capacitor, E.F. 

JOHNSON 167-104-1 

S1 DPDT selector switch 



Fig. J. Schematic diagram. 



.. . K3SCW/AFA3SCW 



116 



73 MAGAZINE 




ECTRIC 
XTENSION 



BUI Welsh W6DDB 
2814 Empire Avenue 

Burbank, CA 91504 



CORDS 



It has been said that "familiarity breeds 
contempt" and also that "a little know- 
ledge is a dangerous thing." Both seem to 
combine to cause hams to use extension 
cords improperly, WeVe familiar with wire 

and we know about voltage drops. Unfor- 
tunately, we tend to push extension cords 
past their limits, and this can cause trouble. 
This article contains some information 

which is useful to anyone who uses an 
extension cord — and that takes in almost 

everyone! If you are one of the few wise 
ones who use extension cords properly, you 
are to be congratulated; even if this is the 
case, you'll be sure to know others who can 
benefit from reading this article. 

Wire sizes and gauge numbers run op- 
posite to each other. The larger diameter 
wires have smaller gauge numbers, and vice- 
versa. This article is primarily concerned 
with 8 thru 18 gauge wires and Table I lists 
their diameters in mils. Remember that 1 mil 
is 1/1000 of an inch. 

Wire has a known dc resistance per unit 
length and this value is normally listed in 12 
per one thousand feet. Basically, larger wire 

Table I. Wire Gauges and Diameters 

Gauge Numbers Diameter (Mils) 

8 128,5 

10 101.9 

1 2 B0.8 

14 64.1 

16 50,8 

1 8 40.3 

has less resistance per foot than smaller wire 
because the electron flow has a larger cross- 
sectional area (pipeline) to pass thru. As an 
example, 8 gauge (0.1285 inch diameter) 
wire has less than 1/10 as much dc resistance 
as 1 8 gauge (0.0403 inch diameter) wire. 

If you intend to use an extension cord, 
you'll have to determine the total current it 
will have to handle by adding the current 
requirements of each device you plan to plug 



into the cord. Amperage (current) require- 
ments are frequently shown on equipment 
and in associated instructions. If just the 
power (watts) is shown, divide it by house 
voltage (115) to determine the amperage 
requirement. As an example, a 230 watt 
device draws two amperes from a 1 1 5 volt 
input power line. If you're going to feed a 
motor which doesn't show amperage or 
power data, Table II can be used to estimate 
normal current requirements of motors rated 
at I /6 to 1 full horsepower. 

Use the shortest extension cord that will 
comfortably reach between the available 
power outlet and the electrical device which 
temporarily needs to be powered at some 
remote point. Line loss causes the cord to 
heat up. If the loss is excessive and if it is 
sustained continuously for a long time, the 
overheated cord could damage materials it 
touches and could start a fire. Regardless of 
how short an extension is required, use one 
which has large enough wire to handle the 
total current requirement- If you have to use 
the same electrical device at a location which 
is further from the power source (wall 

Table II. Amperage Requirements of Motors* 

Horsepower Rating Amperes 

1/6 4.4 

1/4 5.8 

1/3 7.2 

1/2 9^8 

3/4 13,8 

1 1 6.0 

socket), it is usually necessary to switch to a 
cord with larger wires. Table III lists the 
gauges of wires required in extension cords 
used to supply 2 — 20 amperes of current 
25-100 feet from the power source. 

Do not use a 2 — wire extension cord 
outside or in any damp inside area. Since 1 
January 1970, the Underwriters Labora- 
tories have required 3 — wire cords for these 
applications. When using a 3— wire to 2 wire 



OCTOBER 1974 



117 



WORLD 





Now that most repeaters have been redeemed and hurv 
drads of new repeaters are on the air, get thrs. the most 
complete list of repeaters available anywhere, and be sure to 
have tt in your glove compartment when you travel, or with 
you when you fry so you know which repeaters to use. 

This new 1974 edition of the Repeater Atlas of all the 
repeaters in the world is just off the press. This edition, with 
the monthly repeater update in the 73 newspages, will keep 
you potted. 
1974 Repeater Atlas of the World ■ ■ m OIVMjV 

Magazine ■ Peterborough NH — 03458 



YOUR GEAR. .. 
We pay top dollar or trade . . 

Tell us what you have — Here's a partial list 
of what we want: 



RT-742/ARC- 

RT-743/ARC- 
RT-823/ARC- 
RT-857/ARC- 
RT-524/VRC 

R-442/VRC . 

RT-648/ARC- 

AN/VRC-24 

CU-1669/AR 

C-6287/ARC- 
AN/PRC-77 . 



51 BX* . . RT-662/GRC-106 

*w/control boxes 
51 A . . . RT-698/ARC-102 

1 31 ... Magnavox FM-622 

134 .. . RT-859/APX-72 . 

. - . RT-246/VRC 

. . . R-390A/URR . . . 

94 . . . AN/TRC-68 

. . . AN/URC-9 . . . 

. . ,49pT-1 ... 61 8T- 1-2-3 

51 BX . . . AN/PRC-25 . . . 
. . Wilcox 807 



We buy all types of military test equipment . . , 
radios, etc. Do you have a TS—683/TSM crystal 
impedance meter, H~P or TEKTRONIX equip- 
ment? If you hate $$$ we'll trade for NEW ham 
gear! But if you love green stuff, let's trade 
YOUR equipment for OUR dough! 

OLUMBIA ELECTRONIC SALES, INC. 

|Box 9266-A; No. Hollywood, CA 9160! 

Phone: (213)764-9030 



Table III. Wire Gauges, Extension Cord Lengths, 
and Current Requirements. 

115V ac extension cord length, in feet. 





A 


T 


M 


O 


P 


JWt 


E 


A 


R 


L 


E 




S 





25 


50 


75 


100 


20 


10 


10 


8 


8 


18 


12 


10 


10 


8 


16 


12 


12 


10 


10 


14 


12 


12 


12 


10 


12 


14 


12 


12 


12 


10 


14 


14 


12 


12 


8 


16 


14 


14 


12 


6 


16 


16 


14 


14 


4 


18 


16 


16 


14 


2 


18 


18 


16 


16 



adapter to connect a 3 wire extension cord 
to a normal 2 wire home power connector, 
make sure to attach the green grounding lead 
(on the adapter) under a screw head on the 
power outlet cover; don t leave it hanging 
loose! 

If you are going to use an extension cord 
in an area where it could become covered 
with water, oil, or grease, select a cord which 
has an outside protective insulation which is 
resistant to these substances. 

Most of the cheap extension cords carried 
in markets can't safely handle more than six 
amperes. If a blue UL tag is attached, it will 

list the amperage , voltage, and wattage 
ratings of the extension cord. The connec- 
tors, of course, usually are rated above the 
capability of the cords they are attached to, 
so one can't assume that the connector 
ratings apply to the entire extension cord- 
It is important to remember that exten- 
sion cords are just a temporary means of 
supplying electrical power to equipment. 
Don't tape or staple an extension cord in 
place, because that would be using it as 
semi-permanent wiring. If you find yourself 
about to do this type of thing, please 
reconsider and have permanent wiring added 
instead. Brightly colored extension cords 
(yellow, red, etc.) serve to remind one that a 
temporary extension cord is being used. The 
white and brown cords blend in too well to 
be noticed. 

Put your knowledge to work to minimize 
risks associated with extension cords. Care- 
fully select the proper cord to serve as 

temporary wiring in each appli cation. Pass 
the word along to your relatives and friends. 

Extension cords don't cause troubles, but 
their incorrect uses do. 

. . .W6DDB 



118 



73 MAGAZINE 



Hugh Ailken WA1FBE 
85 Dana Street 
Amherst MA 



Longer Tube 

Life With The NCX-5 



Would you like to get more power out 
of your National NCX-5 trans- 
ceiver? It's not difficult, now that 
6LQ6/6JE6 TV sweep tubes are available for 
use in the final amplifier. Write to the 
National Radio Company in Melrose, 
Massachusetts, and they'll send you a bul- 
letin specifying the minor circuit changes 
necessary. You have to change the bias 
resistor (R-36) to about 68K, substitute 
larger plate caps, and modify the power 
supply so as to give between 950 and 1000 
volts on the high voltage side under load and 
300 volts on the lower voltage side. Screen 
voltage should be no more than 200V. Tune 
for 400 mA at resonance and you should be 
able to get between 400 and 500W PEP 
input or about 275W output. Better keep a 
fan or blower on the 6JE6 c s, though, while 
you're getting everything set up, or you may 
lose your first pair of tubes. 

The National company doesn't recom- 
mend this modification, but it's a simple one 
to make. The question is, is it worth while? 
Is the extra power worth the trouble? 
Doubling power is only a 3 dB gain, or 
one -half an S-unit. If you're already running 
200W input, the only place to go is to a '*full 
gallon" if you really want to make a 
difference* Or maybe your time and money 
would be better spent improving your an- 
tenna. 

When 1 put 6JE6A*s in the final of my 
NCX-5, my purpose was not higher power 
but longer tube life. My rig first emerged 
from its carton with 6JB6's in the final. I 



operate CW almost exclusively, and that 50 
to 75% duty cycle was rough going for a rig 
designed primarily for single sideband. Fre- 
quent tube replacement was costly and a 
nuisance — doubly so because of the neces- 
sity for securing a balanced pair, Reduced 
loading of the final was definitely not the 
answer to this problem; underloading meant 
excessive screen current and shorter, not 
longer, life. 



6JE6A 




Fig. J. 



-80 VDC 



Availability of 6JE6's offered a way out 
of this difficulty, but not until after an 
educationsal QSO with Steve Lawrence 
WB6RSE, then a senior at U.CL.A,, and 
some subsequent correspondence did I get 
the minor circuit modifications figured out. 
You have to modify the bias circuit a little, 



OCTOBER 1974 



119 



DATA 
SIGNAL 

the latest in station accessories 

AUDIO AUTOMATIC GAIN 
CONTROL AMPLIFIER 

Is your tone decoder having problems due to in- 
put signal variations? if so, eliminate these and 
other problems caused by weak, strong or vary- 
ing input signals. The AAGC-1 will take signal 
levels between 50 mV to 5 Volts and feed a 
clean rock stable signal to any decoder for per- 
fect operation. Give your decoder a chance to 
decode properly with our AAGC1 amplifier. 

Shipping Weight 3 gz. $14.95 kit 

$19.95 wired 

DELUXE RECEIVER PREAMPS 

Specially made for both OLD and NEW receivers. 
The smallest and most powerful single and dual 
stage preamps available. Bring in the weakest 
signals with a Data Preamp, Now with im- 
proved FET's for greater performance. 



BAND 


STAGES 


GAIN 


NOISE 
FIGURE 


KIT 
PRICE 


WIRED 
PRICE 


10 meter 


Single 


25 dB 


2 dB 


$15,50 


$18.50 


6 meter 


Single 


25 dB 


2 dB 


$15.50 


$18.50 


2 meter 


Single 


20 dB 


2.5 dB 


$15.50 


$1850 


2 meter 


Double 


40 dB 


2.5 dB 


$3050 


$36.50 


220 MHz 


Single 


17 dB 


2,5 dB 


$15,50 


$18,50 


220 MHz 


Double 

i 


35 dB 


2.5 dB 


$30.50 


$3650 



CRICKET 1 ELECTRONIC KEYER 

A popularly-priced IC keyer with more features 
for your dollar. Cricket I is small in si2e and 
designed for the beginner as well as the most 
advanced operator. It provides fatigue-free send- 
ing and its clean, crisp CW allows for easy 
copying at all speeds. Turned on its side, the 
Cricket can be used as a straight key for man- 
ual keying. Right or left hand operation. AC/DC. 

Shipping Weight 3 lbs. $49.95 
OTHER EXCITING PRODUCTS INCLUDE 

TOUCHTONE TO ROTARY CONVERTER 

TOUCHTONE TO TOUCHTONE CONVERTER 

TOUCHTONE PADS 

AUTOMATIC DIALER 

ANTI-FALSING TOUCHTONE DECODER 

AGC AMPLIFIER 



Write today for complete details 

Data Signal, Inc 

Successor to Data Engineering, Inc. 

2212 Palmyra Road 
Albany, Ga. 31701 

912-435-1764 



but adding a 4.7K resistor between R*l, the 
bias adjustment potentiometer, and R-54 
will take care of that in most cases (Fig. 1). 
The essential change is in the screen supply. 
Here you have to provide 1 50V regulated on 
transmit, instead of the approximately 250V 
the old 6JB6's used. Add a 3K 1QW resistor 
to the screen supply and regulate it with a 
1N1812A zener, and you've got it (Fig, 2). 



RI99 
(OCLfL 



T 



C42 



C4£ 



3K 

IOW 

(ADD) 





VI 
6JE6A 



JNI0I2A 
(ADD) 



Fig. 2. 



+ 220 T 



m 



The zener mounts very easily by slightly 
enlarging one of the ventilating slots around 
the final tube sockets, and can be used as a 
tiepoint for the rest of the rewiring. Clip the 
220T side of R-199, connect it to the zener, 
and add the 3K resistor between the zener 
and the former 220T tiepoint. This should 
do it; if your idling current is still too high, 
adjust the values of R-36 and R-37 until you 
get the proper reading (50 to 60 mA). 

You will probably have to retime some of 
the driver coils (L-l through L-5). Carefully 
peak the * 'exciter tune" control first on each 
band, and then tune the appropriate driver 
coil slug with a plastic alignment tool 
through the holes in the enclosure. Adjust- 
ment of L-6 through L-10 is not necessary. 

Of course you can always, if you like, use 
6JE6C*s, and step up your plate voltage and 
current to get between 400 and 500W input 
to the final, but what's the point? Leave 
your power supply unmodified, make the 
minor changes in bias and screen supplies 
outlined above, and with 6JE6A 5 s in the 
final you can forget about short tube life — 
and about matched tubes as well. These 
bottles will take a tremendous amount of 
abuse, and they seem to last forever. If you 
operate CW, own an NCX-5, and like tubes 
that won't quit, give this simple modifica- 
tion a try. 

; . .WA1FBE 



120 



73 MAGAZINE 



Joe Kasser G3ZCZ/W8 

1 951 9 Cranbrook Drive, Apt. 216 

Detroit MI 48221 



Aoartment 



AN 




i 



ers 



NNA SYS 




The basic requirements for an apartment 
dweller's antenna system are 1) the 
antenna shall put out a good signal, i.e. If a 
station can be heard he can usually be 
worked, and 2) the antenna shall be as 
inconspicuous as possible so that neighbors 
and your landlord do not object, particularly 
where the apartment lease forbids antenna 
installations. 

System Testing 

The antenna is tested during a period of 
high activity on the various bands — during a 
contest. The contest period is chosen so that 



ANTENNA 




ROOF 



RESONATOR % 
COIL 



MAST 



I HOOK 






/STRING 






?L0OP 






\ 30* 
\ 

FM IMPPD f 


CLIP 
LEAD 


WINDOW 
FRAME 



MOUNT 



WINOOW 
LEDGE 



Fig. 2. 



COAX 



reports from a large number of stations can 
be obtained in a relatively short period of 
time. Note that the failure of a station to 
respond to a call is a valid * "negative" report. 
The invisibility of the antenna is tested 
by usage. It is only visible during actual 
operating periods. If at those times it is 
inconspicuous, then no complaints will re- 
sult. If after a month or so no complaints 
have been received, the test is successful. 

System Description 

The antenna used is a Hustler mobile 
whip, operated out of an apartment window 
at about 25 ft above ground as shown in the 
sketch- This antenna system was chosen in 
preference to others because it was easily 
collapsible and did not fall down under the 
weight of ice or due to the effects of winds 
or large trucks, as did earlier long thin -wire 
arrays. 

Setting Up 

Attach a hook or other fastening element 
to the wall or roof outside the building 
above the window. If a convenient tie point 
is available, it may of course be used. A 
piece of string is tied to the hook and a loop 
about 3 in. in diameter is tied in the other 
end of the string. The mast is screwed onto 
the bumper mount and laid to one side. The 
resonator element is passed through the 
loop, then screwed to the mast. The antenna 
is then pushed out of the window and the 
bumper mount placed on the windowsill.The 
mast is supported by the string. The window 
is then closed, wedging the antenna in place. 

The first time the antenna is used, the 
length of the whip is adjusted for minimum 



OCTOBER 1974 



121 




■ ■OhbrhC 



1 1 H»JI1 iNt L|< in ifiF vtmrr 1**1 U# hm. 



HAWFE5T UuilTltr ^„ f k ( 1 inM frtH 



LVmLirca 



V«*W ill llw AinJ 



The ?3 HOTLINE it published every athif Fridny. This nertslcttnr 
will c:jw«h pll ihe up to 'the minute happenings In amateur radia, , , 
FCC IWW»„ , .fiirw pBtili-nm ftted, . .mtw Mniom. . .Dx^tid iimns. 
imw products. . .prcpsgatiom flashes, . .Ho Mine Claasiiif?:! .jds. . .joli 
oppofTUrrtlJts in Che haul field, . .hemfeii And tottvnrittan nrw;. , 
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newsletters ane f but will be similar \® the lormai Of ni?wUJ9pe-ra, 
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swr in the same way as is done in a mobile 
installation. 

Dismantling the antenna just requires 
opening the window and pulling it in. The 
string may be left hanging or tied down to 
the window frame by catching it between 
the window and frame when the window is 
closed. The whole operation of erecting and 
dismantling the antenna takes only a matter 
of seconds. 

Using the Antenna 

In order to keep the antenna inconspicu- 
ous, the 75 and 40 meter resonators are used 
only during the hours of darkness when the 
whole antenna cannot be seen. By day, the 
small size of the 15, 20 and 10 meter 
resonators keeps the antenna inconspicuous. 

In use it is possible to alter the effective 
angle of radiation of the system by varying 
the length of the string so as to change the 
angle of the antenna with respect to the 
vertical position. 

Results 

Any antenna system is judged by its 
performance. This one was tested during two 
contest periods driven by a Yaesu FT 101 
barefoot with the following results: 

(1) CQ WW DX Contest, October 1971, 
worked Europe, Africa, North, South and 
Central America. Did not hear Asia or 
Oceana. CR6, XX6 3 8P6, 9Y4, EA, ZF and 
CT were worked on 20m alone. 

(2) ARRL Sweepstakes, November 1971, 
worked 63 Sections, 45 States including 
California on 40m, and all Canadian Sections 
including VE8. 

During both of the above contests several 
pileups were heard and with careful timing a 
contact was made in most cases. 

No comments or complaints as to the 
antenna have been received up to the present 
time. 

Conclusions 

The apartment dweller's antenna system 
puts out a good signal on all bands. While it 
will not replace or outperform a beam or a 
quad, it does allow transmitting operation 
under many unfavorable (to the amateur) 
conditions, 

. . .G3ZCZ/W8 



I 



122 



73 MAGAZINE 



MY HAM'S 



OLD 



Ms XYL E. A Gray 
8955 East 83rd Street 
Ray town MO 64138 



SHACK 



AND 



OTHER 



ABOMINATIONS 



What's a nice girl like me doing in a 
place like this? All this squealing 
and dah dits and WA0*s and interference and 
skip is enough to drive a strong woman up 
the wall and upside down across the ceiling. 
That's what happens when an unliberated 
female enters holy wedlock with an (in 
deep) ham operator , Of course you get used 
to it as you learn patience, fortitude and 
create a sense of humor out of hysteria. 

I've learned patience so well I can sit 
calmly — my fingernails actually growing 
through my clenched fists — with my face 
deceitfully expressing a serene concern and 
interest in whether we should go FM, get 
involved with the repeater, go mobile, buy a 
crankover or ground plane, etc. 

My fortitude has given birth to a kind of 
patience of Job, as one by one the absolute- 
ly -had-to-have transceivers, converters, moni- 
tors and rectifiers have decayed into a state 
of abject obsoleteness. Funny how old fur- 
niture and clothes never reach that stage, 
isn't it? "Lots of wear in it yet," my 
operator always says. 

My sense of humor actually came from 
the need to laugh or, for crying out loud, go 
with the boys in the white coats. When a 
friend comes to dinner, a guess-what-kind-of 
operator of course, and I ask, '*Have you 
heard that new rock group, the *Whatchama- 
callits'?" and he replies, "Yeah, they got 
great rhythm," then turns to his host and 
says, "If we could get a bigger transformer 
and raise the beam another ten feet and 
convert the , , - " I need a sense of humor. 



When I ask sweetly, "Did you see the 
home team beat the tar out of those 
smart-aleck West Coast bigots?" and he 
answers, "Man, that new quarterback is 
suinpin' else," and adds, eyes on fire with 
excitement, "I think I've got a chance to 
trade for a new so many meters with a 
vertical something or other and a matching 
thingamajig," that's my cue to exit to a 
quiet place or visit with my English-speaking 
neighbors. 

At night I go to bed by myself or watch 
ziggagging or growling TV while my operator 
calls nets, has roundtables, turns rotors, 
cranks beams or has eye-balls. 

From a cute little boy who fastened two 
tin cans together with a string and yelled 
into one, "CQ, CQ, CQ," and listened to the 
imaginary answer, he has lived his life by 
wire and put me at a tension that is getting 
ready for a mighty recoil* 

Out riding in the beautiful countryside, I 
cry "Oh, look at that gorgeous ..." and he 
hisses, "Be quiet, that's old WA0BVD, or is 
it CWE, who helped me with my first two 
meter kit. Break, break!" Speaking of 
"break/* I sometimes have an overwhelming 
desire to break - well, almost anything. 

A friend asked, "Why don't you leave 
him?" Well, I've given it some thought, but 
I'm an unfortunate orphan with no place to 
go and too big for adoption and besides I 
love the ham, who occasionally tunes into 
my wavelength and generates a little 
"Switchcraft." 

. , ,XYL Gray 



OCTOBER 1974 



123 



Bernard Ostrofsky W9HTF 
670 N. Tippecanoe St. 
Gary IN 46403 



AUTOMA 




VERTICAL 



TRIGGER FOR 




In order to improve the vertical sweep 
function of a slow scan TV receiver 
converter 1 the circuit shown in Fig. 1 was 
constructed. The vertical retrigger consists of 
QK Q2, and Q3. If output is taken from Q3 
it would be necessary to reverse connections 
to the vertical plates of the cathode ray tube 
due to phase inversion. In order to eliminate 
the problem so that the oscilloscope used 
with the SSTV converter could be used 
without reconversion for normal response 
the operational amplifier stage was added- 

The wave forms shown in Fig. 2 indicate 
the output from the original vertical sweep 
circuit (non-recurring) output from Q2 and 
from the op-amp. The negative bias applied 
to the inverting input of the op-amp restores 
the polarity and makes the wave form 
congruent with the original. The SOOOH 
potentiometer is set for a sweep period of 
8.5 seconds. 



■o*J5V 



2M6008 

2N3392 

01 




ICI-OPER AMP M A74t OR ^A 709 
ALL RESISTORS- 1/4 WATT 



H5V 



-J5V 6 
♦ 15 V 



The original circuitry to be replaced is 
shown in the broken line box in Fig. 3 along 
with the points for connecting the input and 
output. 



ORIGINAL 
CIRCUIT 



OUTPUT 
FROM 02 



OUTPUT 
ICI NO BIAS 
AT INVERTING 
INPUT 

OUTPUT 
ICI,-I5V BIAS 

AT INVERTING 
INPUT 






Fig, 2 # Vertical output wave forms. 



IN9>4 






JJS.8 







Fig. L Automatic vertical trigger circuit. 



Fig, 3. Circuit replacement points* 

The entire unit was built on a 1 x 2.5 in, 
piece of perforated Vectorboard and 
mounted directly above the original com- 
ponents, 

. . -W9HTF 

L Briles, Bill and Gervenack, Robert. M Slow-Sean 
TV Viewing Adaptor fur Oscilloscopes" QS7\ June 
1970. pp 46-50. 



124 



73 MAGAZINE 








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OCTOBER 1974 



125 






>. 



George R. Men W1HC1 
80 Farmstead Lane 
Windsor CT 06095 




The New 



2 m FM has produced some drastic 
changes in amateur radio. No longer is 
the radio amateur limited to communication 
from his home station or from 
his car. By using small hand held units on 
2m, the amateur can carry on communica- 
tions from areas which were inaccessable in 
the past from a communications standpoint. 
Communication via hand held units is not 
only useful from a "rag chew ,s standpoint, 
but is extremely valuable in times of 
emergency or disaster. Because of the heavy 
participation of hams in times of emergency 
it has become the goal of most amateurs 
who operate 2m to own some type of hand 
held equipment Unfortunately, most of the 
equipment in this category is somewhat 
costly being in the $200 and up range and 
the majority of the HTs are made outside 
the country. In addition most of the hand 
held units cannot be maintained by the 
average ham. In cases where a problem 

develops, the unit must go back to the 
factory. Since the units are foreign made, it 
is difficult to obtain spare parts or vital 
subassemblies. For these reasons, a large 



HT-144B 



Hand Held 



number of 2m operators have put off the 
purchase of that desirable "HT. M 

VHF Engineering in Binghamton NY has 
introduced a low cost hand held kit for 2m 
which almost every 2m amateur should be 
able to afford. This kit provides a simple, 
inexpensive answer to 2m FM operation. 
The unit is designated the "HT-144B" and is 
described in detail in this article, 



Specifications 

The HT-144B is manufactured by VHF 
Engineering in Binghamton NY and is avail- 
able in kit form through the manufacturer or 
through dealers across the nation. The kit is 
very complete and includes all parts except 
the nicad batteries and the charger. These 
items are available as accessories. One set of 
crystals is included, your choice of 94-94, 
52-52, or 34-94. 

The transmitter puts out a minimum of 
2W on one of four crystal controlled 
channels at 2m. Modulation is accomplished 
by using a speaker/mike into an amplifier 
driving a varactor modulator Netting 



126 



73 MAGAZINE 



trimmers are provided for all four channels. 

The receiver is rated at 35^V for 20dB 
quieting and puts out ,5W of audio, .25 
squelch/sensitivity. A pair of crystal filters 
provides adjacent channel rejection of 60dB. 

While four channels may not seem to be 
enough, most HT owners that I talk to say 
that four channels are sufficient But no 
matter how many channels you have, you 
wish you had more. By limiting the number 
of channels to four, the manufacturer has 

kept the cost of the unit to less than $130, 
This is a remarkable buy in these times of 
inflation. 



Construction 

The HT-144B consists of a main PC board 
on which afl components are mounted and a 
tiny PC board for the crystals and the crystal 
switch. The main PC board is made of epoxy 
glass and has the parts layout silk screened 
on the top. By using a silk screened board, 
the manufacturer has simplified parts place- 
ment and the overall construction of the 
unit. Parts layout is good and not crowded. 

The case is made of black, wrinkle-finish 
aluminum and is very rugged. The case is 
large enough for the boards and the batteries 
and has a considerable amount of room left 
over to house PL tone encoders and the like. 
The outside of the case is smooth and has 
enough area to hold a sm^ll touch tone pad. 
There is a jack on the top for use with the 
optional battery charger. The HT-144B 
comes with a telescoping antenna. However, 
an external antenna or a stubby flexible 
antenna may be used by mounting a BNC 
connector in the 95mm (3/8") hole pro- 
vided. 

The HT-144B is very easy to build and 
can be constructed by anyone who has had 
minimal experience building kits or ham 
equipment This kit, however, is not for the 
arm chair amateur as it requires some 
knowledge of schematic diagrams and the 
ability to solder with a low wattage soldering 
iron. The only tools needed are a soldering 
iron (26W preferably), solder, screw drivers, 
pliers and wire cutters- Construction time 
for the average ham should run about 7 to 
1 2 hours. The instruction manual is clear 
and concise. 



Theory of Operation 

The transmitter consists of 7 transistors 
in a unique design. A speaker/mike drives a 4 
transistor cascaded amplifier which in turn 
modulates a crystal oscillator with a varactor 
diode giving true FM. The oscillator uses 
18MHz crystals and quadruples to 72MHz. 
The second stage doubles to 144MHz and 
drives the 2N5389 to 2W output Both the 
oscillator and driver use the readily available, 
inexpensive 2N3866, The output stage is 
somewhat under rated and because of this 
does not need a heat sink. All stages are 
optimized to conserve battery current 

The receiver uses a MOSFET front end, 
3N204, and has more than enough gain for 
the first mixer, a 2N5222. The first mixer 
feeds a pair of high quality 2-pole crystal 
filters at 1 0.7MHz, The second mixer is a 4 
transistor cascaded limtter/i-f stage feeding a 
ceramic discriminator at 455MHz. The audio 
output IC is a readily available MFC6070. 
The squelch circuit consists of a noise 
amplifier which amplifies high frequency 
noise. The presence of noise causes a 
MPS5172 switch to cut off the MFC6070. 
The absence of noise, such as when a signal 
is present, causes the MFC6070 to be turned 
on. Squelch operation is smooth and reliable 
with this circuit. 

Switching is accomplished with a double- 
pole double-throw switch mounted on the 
side of the main PC board. Both antenna and 
battery voltages are controlled by this 
switch. 



Performance 

I built my unit without benefit of an 
instruction manual since I managed to 
scrounge a pre-release unit so I could write 
this article. The only problems that I had 
were one bad solder joint and one misplaced 
component These problems were found 
quickly with the help of a 10MHz scope 
once the batteries were connected to the 
unit. In practice, a scope or other sophisti- 
cated tool should not be needed if a little 
care is taken with component placement and 
soldering. The PC board has the placement 
of all components marked clearly, so it is 
next to impossible to make a mistake unless 
you rush as I did. 



OCTOBER 1974 



127 



Tune up is very simple. The instructions 
call for the use of a signal generator to tune 
up the receiver, I don't think that the signal 
generator is really necessary, since 1 found 
that even in the untuned condition I could 
copy signals several miles away. So, I tuned 
my receiver up on the air. 

Tuning up the transmitter is also very 
simple. Merely connect a wattmeter or a 
light bulb (#47 bulb) to the output connec- 
tion and tune for maximum output A 
voltmeter is useful to help tune some of the 
coils, but may not be necessary in all cases. 

My HT-144B measured 2.2W out on a 
Bird termiline wattmeter. The meter 
measured .3juV for 20dB quieting and the 
squelch opens at .2(jlV. I have used this rig in 
the Hartford area for several months now 
with excellent success. I have owned other 
HTs in the past and I feel that this unit will 
equal anything on the market today. The 
unit meets all advertised specs as far as I can 
determine. The only complaint that I have is 
that the transmit audio is slightly bassey, but 
not to an objectionable degree. This is 
typical of HTs using a speaker/mike. 

Up to 6 kc deviation has been provided 
showing quite an improvement over the 
earlier HT-144. 

Conclusions 

After having built and operated my VHF 
Engineering HT-144B, I am very pleased and 
feel that it is a best buy in HTs at this time. 
You can't even come close for less than 
$199.00. I do offer a few cautions however. 
Schematic reading ability is not an absolute 
requirement for building this kit, However, 
the ability to properly solder is. You must 
be able to solder without dropping globs of 
solder all over the board and without apply- 
ing too much heat to the components on the 
board. 

After building this HT kit you will have 
an inexpensive, well performing unit that 
you can repair yourself. 1 recommend it 
highly. ,,.W1HC1 

CRYPTOGRAM 

ZSEDSF USZZQVS CDKU MJYXOG 
SXJFKD; ZBQLS HL KD SOZS! FSOO FBS 
XQUYSX CEE ABQF GKH FBJYM DS 
LDKLKZSX DSVZ. 



Joseph A. Kramer WA9DJR 
14 East Jackson Blvd. 
Chicago IL 60604 



TVI 
FIXIT 



Recently I purchased one of those 
"gizzards in a box" transistorized TV 
sets for the XYL and paid enough to get that 
commercial linear; When I stayed on CW I 
was in the clear but when AM or SSB, that 
TV tuned as broad as a barn and a high pass 
filter didn't help. 1 knew my rig was clean 
and two black and white sets had no 
interference. What to do? 

I made up a three wire short line cord. 
Four feet long, to be exact, and covered it 
with the braid from a piece of coax. The 
plug I used had a two screw metal clamp and 
the braid was placed just under the metal 
ring. Green wire to green plug terminal, 
white to white, etc. At the" 1 other end I 
attached one of those noise filters that are 
quite plentiful in surplus, white and black to 

the input and the braid soldered to the case. 
I cut the TV cord short (about 9 inches) and 
soldered it to the output terminals of the 
filter. The interference filter was attached to 
one of the back screws that hold the back 
firm at chassis, Another wire grounded the 
power supply and the set chassis. While I was 
at it I put a small fan underneath the cabinet 
to carry off some of the heat, since I was 
surprised how hot the wood cabinet was 
when operating. 

No TVI, and what a beautiful picture 

improvement. Fantastically true colors, a 
new revelation in color TV, Not to mention 
a happy XYL, and the OM can operate 
again! 

...WA9DJR 



128 



73 MAGAZINE 



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Cassette HQ - Box 431 - Jaffrey NH 03452 




Gerd Treuhaft 



FIRST 






Beefeater Roy Reed is really quite a ham 
and in fact the real Tower Hamlet. He is 
better known as Yeoman Warder Reed on 
duty and G3 LEX off duty to his many 
friends on the amateur bands all over the 

world. 

When Roy became a Yeoman Warder in 
June this year, he moved into the Tower 
with his wife and daughter, becoming the 
first Radio Amateur at the Tower of 
London. He has, with the Tower of 
London's co-operation, been able to erect a 
108 foot long antenna behind the battle- 
ments in the N.E. side of the Tower. 




U 



O.P.S. Yeoman Warder Reed on the battle- 
ments with the antenna stretching 108 feet. 

"It's quite funny on occasions," says 
Roy. "I call on the wavebands and when I 
establish contact and tell the receiver where 
I am calling from he either doesn't believe 
me or thinks I'm mad and closes down. 
There was one instance when we made a link 
between 4 hams all named Roy, so I was 
immediately named Raven Roy for identifi- 
cation!" 




130 



73 MAGAZINE 




PHILADELPHIA ATTROCITY 

A letter from W3ZWR/2 tells of a 
most frustrating situation, I gather 
from his letter that his mother-in-law 
was somehow involved in notifying 
the police that Gene's car was an 
abandoned car. The police came to 
tow it away, despite efforts of his wife 
to stop them. Gene is crippled, so 
there wasn't much he could do. The 
police never even tried to verify the 
complaint about the abandoned car. 

The car contained reference books, 
hundreds of tubes, some television 
sets, some FM equipment, both base 
and mobHe rigs, plus a good deal of 
surplus gear - all of which was 
apparently stripped after the car was 
seized by the police. It also appears 
that Gene is just plain out of luck on 
collecting anything from the city for 
the outrage. It would seem that it is 
about time for Gene to consult the 
Legal Aid Society and find out what 
his rights really are. 

THINGS LOOKING UP 

The barrage of newly proposed 
changes in FCC regs seems to indicate 
that there are indeed better days 
ahead for us in amateur radio. The 
restrictrveness which was stifling us 
just a few months ago has given away 
to a policy of allowing amateur radio 
to grow. Since this change in basic 
attitude has taken place under Chair* 
man Wiley, it may be that we all owe 
him a debt of gratitude- 

The virtual elimination of the 
togging requirements, the purpose of 
which had been lost somewhere in 
history, is a good sample, I talked 
with the Amateur Division about this 
a couple years ago and asked why we 
needed to keep logs in such detail. 
The answer seemed to be r "Because 
thats the way it's always been." I 
wrote and editorial on the subject. 

Most of the seriously restricting 
repeater rufes have now been amended 
or are about to be amended, as 
promised us by Chairman Witey back 
in January when we held the hearing 
before the Commissioners. This has 
turned things around for the FM boys 
and repeaters are going in at a faster 
clip than ever before. FM was, even 
then, the largest single interest in 
amateur radio, with about 40% of the 
active amateurs participating — now 
this is heading higher and the day may 



come when almost every active ama- 
teur has a VHF transceiver in his car 
and an HT on his hip at hamfests. 

The repeater growth here in New 
Hampshire is rather typical, I think. It 
wasn't very many years ago that there 
was a 34/94 repeater in Concord (the 
state capitol) and that was it. A 
couple years ago we had five 
repeaters. Today we have nine on the 
air and three more due on any day. 
When you consider that there are only 
about 1550 licensed amateurs in New 
Hampshire all told, a fair percentage 
of them must be active on FM to keep 
twelve repeaters in action. 

Unless Dean Birch ends up with 
more power than it appears he will 
with the collapse of the Nixon 
administration, it is possible that ama- 
teurs will retain the 220 MHz band. 
Should this come about, it now seems 
likely that my proposal for a code-free 
beginners ticket will materialize which 
will permit operation in that band. 
The ARRL is very much in favor of 
this move (which goes to prove some- 
thing, probably) and has their direc- 
tors out talking it up at clubs, 

Oddly enough, I view the code-free 
license with less than total confidence. 
There is no question that we need 
more amateurs and need them desper- 
ately — and there is little question 
that the opening of a code-free band 
would become popular, My reticence 
has to do with the results of my 
recently devised code tapes. The fact 
is that teaching methods have come a 
long, long way in the last generation 
and with the newest of techniques it is 
so incredibly simple to learn the code 
that a ten year old can do it in about 
one hour — and that's complete with 
26 letters, ten numbers and punctua- 
tion! 

My five word-per-minute beginning 

one hour tape cassette has been bring- 
ing in letters from all around the 
world saying how easy it is to learn 
the code now that there is a tape like 
this. Kids of eight and nine have been 
mastering the code with one playing 
of the 60-minute tape! This leads me 
to wonder just what all the fuss is 
about learning the code a 5~pen It 
now appears that the major difficulty 
with learning the code in the past has 
been the lack of any really good 
system for doing it. Just as the 73 
license study manuals broke the back 
of the theory exams, the 73 code 
tapes have mercifully eliminated the 
problem of learning the code, 

To.digress for a moment. There are 
four tapes available — with the first 
being for someone who does not 
know the code at all. In one hour 
most people are able to recognize all 
of the characters they will need to 
pass the exam for Novice or Tech. The 
next step is our nasty six word per 



minute 'Back Breaker/ This one, 
using the FCC standards of timing for 
both words and individual characters 
(as far as I know this is the only tape 
ever made available which adheres to 
these standards) and thus properly 
prepares you to face the FCC. The 
BB-6 tape gives you one hour of 
unrnemorizable code groups for prac- 
tice and, when you can handle it, you 
can walk confidently into any FCC 
office anywhere and know that you 
will pass their test easify. 

The 14-per tape gets you ready for 
the General and Advanced tests and 
has that margin built in which permits 
you to relax when the FCC tapes start 
grinding. Ditto the 21iDer tape. 

Yes, I know all of the arguments 
against code, and some you haven't 
even thought of yet And I know all 
of the arguments for retaining the 
code as part of the amateur license 
{and there aren't very many legitimate 
reasons), My own reaction to the 
whole situation is to be in favor of 
maintaining the 5 wpm entrance exam 
to the hobby and then depend upon 
the enthusiasm of CW operators to 
encourage higher speeds. 

Since I have recently made up a 
tape of the Novice theory I am rela- 
tively familiar with the requirements 
along that line — and they are not 
much more than one gets in high 
school physics. It thus seems to me 
that if we settled upon a beginning 
license which had the requirements of 
the present Novice ticket, but which 
permitted phone operation in the 220 
MHz band, we might end up with a 
good workable result. Licensees would 
have had to study a little and learn the 
basic- of theory and code, which 
hopefully might separate them from 
the CB buy -your license (or why-buy- 
your-hcense?) crowd. 

There are over 5000 ham clubs 
around the country and, with a little 
encouragement from the ARRL, I 
suspect that a great many of them 
could be cotten to set up Novice 
study classes. As Novices they would 
be able to work phone in the 220 
band and CW on the lower bands, thus 
getting both sides of amateur radio. 
Well, it's a thought, 

73 GROWING, TOO 

About the only thing really hurting 
in amateur radio today is DX, and 
even that is not in too bad shape. The 
dearth of sunspots has made it a bit 
more difficult to work 350 countries, 
but somehow new ones keep turning 
up. 

Now that the IRS hassle seems to 
be over and a couple of very produc- 
tive people have been added to the 
staff, we're looking forward to a great 
fall and winter. I have a bit more time 
to help with the editing and this may 



OCTOBER 1974 



131 



make the magazine a little more fun 
to read, We're looking hard for people 
who would like to represent 73 
Magazine at hamfests and other ham 
events to sell subscriptions, books, 
study guides and tapes. It's a nice way 
to make some money and get to meet 
everyone, If your club is going to have 
any sort of event, be sure to get in 
touch with us and set up a 73 booth — 
\tpays, 

WAYNE TAKES PICTURES 




Henry VflAUY, motorcycle number 73, 
stopped by the 73 offices for a visit. Henry 
can be worked via WRIABU in Concord NH 
most any day. 




Rag K1IGF, one of the very active repeater 
owners of New England, particularly on 450 
MHz. You 11 hear Ray on 6m a lot too f as 
well as 146.52 via a very effective remote 
base setup. 




Kathy WBBLOZ and Sue WBBOXB snapped 
at the 73 booth at Dayton, The next time 
some CBers starts giving you that stuff about 
the code being just too much for him, puU 
out this picture and ask him to explain how 
come these two nice lit tie girls can cut the 
mustard when he can *t. 




Here is WIEFF of the Northern Berkshire 
Amateur Repeater Club - picture taken at 
one of the 73 Magazine FM Symposiums. 





WAIEQN, Nick, of the WR1ABT, New 

Ha ven* 



John Kl HZN. 





Tony, WA1QND, also of WRIABT in New 
Haven. 






Lew McCoy W1ICP, secret 73 double agem 
operating out of ARRL HQ. 





Dick K1ABR, one of the earliest repeater 
pioneers of Rhode island. 10-70 continues 
therewith WR1ABW. 



Ed Cieqg W2L0Y* designer and father of all 
those nice Clegg rigs down through the 
years, Ed has been one of the most enthu- 
siastic supporters of ham use of the 220 
MHz band and has put the Clegg company 
on the line with 220 transceivers and a 220 
repeater. 




K1REC sent in this shot of a five foot 
aluminum knight in armor. Lord knows why 
he built it. but it does have a "73" on it t so 
huzzah for REC. 



132 



73 MAGAZINE 





1 ■'•"'¥ -•:*>: 31 





Some snaps taken at Dayton - undoubtedly the world's largest flea market. Some people come bringing truck loads of stuff 
to sell — some go away taking truck loads of sfuff they've bought - all go away happy. 




Digging hack, here's Johnny Barrows 
DL4HU at Bitburg in 1962 when 1 visited 
him. 





I caught this picture of Ed Pillar W2KPQ at a 
Long Island auction. Vve known Ed since 
before 1 got my ticket - 1 used to visit him 
when I wasanSWLf 





Here's Wayne talking to the Bitburg radio 
amateurs in 1962 - not much change in 12 
years other than a little less hair and weight 



This one was taken by WA8ZCO on 1-75 
north of Lima, Ohio! PR for 73 everywhere, 
if you just keep those eyes peeled. 



CALCULATOR CLOCK 

The Corvus Calculator clock is 
quite unique in concept. The idea of 
combining a clock MOS chip with a 
MOS Calculator Chip appears to be a 
natural. The calculator provides addi- 
tion, su btraction, multiplication, 
square root, division, percentage, 
reciprocals. The unit displays 10 
numerals. The decimal may be set to 
float or fixed at 2 or 4 places rounded 
off to the closest digit. The clock chip 
may be set by a three position switch 
to display time only, date only, or 
alternate time displayed for 8 seconds, 
date displayed for 2 seconds. Clock 
displays hours, minutes and seconds. 
The clock will operate as long as the 
unit is plugged in — the off switch 
serves only to blank the display. In 
the event of power failure the readout 
is all figure 8's, 

For more information write Tucker 
Electronics, P.O. Box 1050, Garland, 
Texas 76040. 



OCTOBER 1974 



133 



HAM 



OOPS! 



HELP 



This column is for those needing 
help in obtaining their amateur radio 
license. 

If you need help, let 73 know — 
don't be bashful — the readers are 
solid gold and are anxious to help 
you, If you would like to help, let 73 
know about that plus your area of 
expertise, if any, so we can list you 
for either general help or as a techni- 
cal advisor. 

The following need some help — 
can you spare some time? Clubs in 
particular take note. 

Charles Zabriskie 
295 Meadowbrook Road 
Weston MA 02193 
617 899-3Q3Q 

Jerry Wilson 
3604 Park Avenue 
Covington KY 41015 
606*431 2320 

Basil W Polinchak, Sr, 
14 Martha Lane 
Lawrence MA 01843 
P0.Box12Q2 

617-68^3910 

Robert M. Gallery 
5013Westport Road 

Chevy Chase MD 20015 




RTTY ART CONTEST 
Sept. 1 to Oct. 31, 1974 

Entries in the contest should be 
sent to Don Royer WA6PIR, 16387 

Mandalay Drive, Encino CA 91316, 
Send a five-level tape and five prints 
of each entry — as many entries as 
you want — winning entries will be 
published in 73 Magazine. Write Don 
with SASE for the full set of rules. 

CONTEST CALENDAR 

Oct 

5-6 California QSO Party 
5-7 WE Phone & C.W. QSO Party 
12-13 VK/2L/Oceania C.W. Contest 
12-13"RSGB 21/28 MHz Phone 
16-17 YLRL Anniv. C,W. Party 



■ 



NOTICE 

Watch for an update of the W0LMD 
SSTV Scan Converter in the 

November issue. 



We left the parts list out of 
KBVIR's article '3000 V DC Power 
Supply' which appeared on page 69 
of the July 1974 issue. It follows 
below: 

BL = Blower, 60 dm at .6 incti static pressure. 
Oayion 4C005 or aquivaJeni, 

Cl ■* Triple-section broadcast capacitor or equiva- 
lent. 365 pF per faction. 

C2 = Jennings 1 to 300 pF Vacuum Capacitor, 6 
kV or higher rating* 

C3 - I5O0 pF air variable capacitor. Spacing 
dependent on tube plate voltage. Air gap approx. 1 
mil/ 10OV of plate voltage. 8&W 51241 or equiva- 
lent, 

D1, D2 # D3 f 04- 1.5 amp, 1000V PIV 

F3 ■ (Slow Blow) Dependant on blower chosen. 
My blower required 2 A. 

J1, J 2 = Chatits-mounting coaxial connectors 
(SO-239K 

L1 = Best, 1/8 inch copper rube silver plated. 
Alternate, No, 10 or 12 copper wire. Approximate 
data 6 turns 1 Vi inch o'iameter, 1% inches long 
tapped 1%, 2, 2% r 4 turns. Note: Trie exact taps 
are dependent on coil placement, lead length and 
driver to linear coax length therefore adjust each 
tap to cover the entire desired band before 
soldering. 

L2 ip B&W S50A. P» network inductance. 

PI = Bmenco Fused Plug, 

Rx = See Text, 

R2 «* Five, 5,6 ohm ftW carbon resistors in parallel. 
Use very short leads. Place XrluFd capacitor 
directly across resistors. 

H5 = Surge resistor. 10 ohm 2W. Note: Check dc 
resistance of your transformer secondary. If it is 10 
ohms or higher disregard R5. 

RFC1 - {B&W FC 30 A) or equivalent. 

RFC2 «■ B&W 800. Note: see text for modification, 

RFC3 - RF choke, Ohmite Z-50. 

Lfl j Lf2 = Line filter choke, Ho. 16 copper wire 
insulated. 20 turns, 3/8 inch diameter close wound. 
(Place filter, Lfl, Lf2 Bt feedthru ,01 capacitors, 
inside bottom chassis at point A-C enters.) 

SI A-B - CRL 2551. 60 degree index, single 
section double pole six -posit ion ceramic rotary 
switch, 

51 C = Switch on back of B&W 850A. 

52 = SPST Toggle switch. 

T1 = 110V primary, 110V sac, 100mA. 

T2 = 7.5V C.T. 21 A, filament transformer. 

TY1 = G,E. Tnyrector i 6R520SP4B4 

Z1 * 2 turns No. 8 copper wire, Vt inch diameter. 
(Silver plated) Shunted by three 130 ohm, 2-watt 
carbon resistors in parallel. 



SATURDAY POST FEATURES 

HAM STORY! 

The DXpedition to Gibraltar 
ZB2CS, is the subject of a feature 
story in the August/September issue 
of the Post* 

For the first time in ages a major 
general interest magazine is running an 
article which talks up amateur radio. 
In this one an American DXer visits 
Gibraltar and tells of his experiences 
meeting a local ham with whom he 
has talked for years — and in setting 
up his ham rig in a hotel and making 
contacts all around the world. 



The article is interesting, too, in its 
coverage of the interesting aspects of 
Gibralter. There aren't very many 
places left where you can stay at one 
of the better hotels for S5 per day 
(with a private bath) and eat for under 
S4 per day. 

If you aren't up to buying this copy 
of the Post to show friends the five 
page article, at least sneak a sub- 
stantial look at it the next time you 
go by a newsstand. One of the 
benefits to amateur radio if someone 
could convince the ARRL to hire a 
PR outfit would be articles like this in 
many more of the general interest 
magazines. It wouldn't take very 
many of these before we had 
thousands of more amateurs joining 
our ranks* It takes PR these days to 
compete with all of the other sports 
and hobbies — and honestly, do you 
know of any other hobby that has as 
much potential for benefit for both 
the individual and the world as ama- 
teur radio? 



NEW 



PRODUCTS 




MODEL #TSL TR I -STAND 
LIGHTPOD 

Just introduced is a new and 
unusual light stand that doubles as a 
sturdy camera tripod, known as the 
Tri-Stand Lightpod. When not in use 
with spots, strobes, or quartz lamps, a 
camera pan head can be quickly 
attached converting the entire unit 
into a rugged camera stand, The 
camera stand will support most 35mm 
and 1 20 size at up to eye level height. 

This precision engineered unit made 
of anodized aluminum will transform 
from its fully extended height to a 
portable system in less than a minute. 
The 3-section column extends from 
41 inches to a maximum height of 
over 9 feet. The famous Safe- Lock 
clutch collar system locks the column 
at your desired height. The tripod 
base is braced with 6 solid aluminum 
struts which lock into place with the 
twist of one control knob. Two inch 
ball bearing caster wheels with toe 
brakes on each wheel allows optimum 
mobility with positive anchoring* 
Gold finished legs and column add 
glamour to what should prove to be 
an extremely useful and versatile 
system. For further information, 
contact: Glenn M. Weft, 
Weft/Safe Lock, Inc., 2400 West 8th 
Lane, Hialeah, Florida 33010. 



134 



73 MAGAZINE 



GUNG HO 

DXers 

Dan Umberger W8ZCQ recently sat 
down and put the ARRL DX listings 
in alphabetical order, thereby dis- 
covering some interesting facts. The 
highest country total is a chap with 
353 (missing one Daimu, whatever 
that is). If Wrangle Island is counted 
(no one has submitted that one), the 
total possible is 355. Thirty ops have 
worked all of the currently existing 
countries, so there is plenty of room 
left at the top. 

Dan counted up the number of ops 
in each call area that made up the 652 
stations listed and found them dis- 
tributed by call area as follows: 



1 - 51 


.25% 


6- 116 


.29% 


2-103 


.31% 


7-20 


.10% 


3-38 


.19% 


8-63 


.22% 


4-94 


.24% 


9^ 63 


.24% 


5 -SO 


.23% 


0- 44 


.17% 



Since the actual number of 
"registered" DXers in any call area is 
not really significant in itself, this 
number has been divided by the 
number of licenses issued in each call 
area to indicate the percentage of 
DXers in each call area. The W2's 
came out way ahead on this, oddly 
enough. The W6's make such a fuss 
about DX that many ops get the idea 
that almost everyone in California has 
a "cool" kilowatt and great big beam 
— and carries around three hundred 
plus QSL's in his back pocket. And 
what happened to seven -land? 

* , , Wayne 

COLLINS ANNOUNCES NEW 
AMATEUR RADIO OPERATIONS 

GROUP 

Cedar Rapids, la., July 9, 1974 — 

Collins Radio, part of Rockwell 
International Corporation, is placing 
increased emphasis on amateur radio 
activities with the formation of a new 
amateur radio business operations 
group. 

Appointed manager of the amateur 
operation is Joe H. Beler W5WY/0, 
who has been with Collins for 14 
years in various program management, 
systems engineering and manufac- 



turing positions, A ham for more than 
30 years, Beler holds an extra class 
license. While serving with the U,S, 
Air Force, where he attained the rank 
of Colonel, he was responsible for 
introducing operational HF SSB to 
the Strategic Air Command, 

Jerry Carter WA0ZRW, who has 
been involved in Collins amateur 
marketing activities for the past two 
years, will be marketing manager in 
the new operation. He has been an 
active ham for 1 1 years. 

Also joining the new business oper 
ation is Arnold Verdow W0LU r who 
will be in charge of product support. 
A long time Collins employee, 
Verdow has been active for many 
years in amateur radio, both with his 
own station and in activities such as 
civil defense. 

The amateur radio business opera- 
tion is a part of Collins' Telecommuni- 
cation Equipment Division based at 
Cedar Rapids, Iowa, 



HEATH 1975 CATALOG OUT 

While Heath may be pushing the 

calendar a little by dating their new 
catalog 1975, the fact is that it is a 
whopper and has some interesting new 
Heathkits featured. This one runs to 
80 pages and covers everything they 
make, including the ham gear, the 
hi-fi, test equipment, right on up to 
their $1000 color television set kit! 

Some of the new gadgets include a 
space-age design digital clock/aiarm 
clock, a matching digital clock/day- 
date unit, a ten watt 2m amplifier for 
HT's - things like that 

It takes strong willpower to pass up 
some of the fascinating Heathkits such 
as the indoor/outdoor digital ther- 
mometer, the three band CW trans- 
ceiver for portable QRP work, and 
their new high power stereo FIVt 
receivers. Heath Company, Dept. 73, 
Benton Harbor Ml 49022, 

THINK METRIC!! 

The metric system, being inevitable, 
as must be obvious to everyone by 
now, it behooves us all to learn and 
relearn a few things. For instance, 
re-gear your thinking to the following: 

A miss is as good as 1.609 kilo 
meters, 



Take it with a decigram of salt, 

He was beaten within 2.54 centi- 
meters of his life. 

28.350 grams of prevention are 
worth 453,59237 grams of cure. 

Peter Piper picked 8.81 liters of 
pickled peppers. 

And how about a girl who measures 
,9144, .6604, .9144?? 

CCRC 

Cont'd from p. 5 

LETTERS 

DX STATIONS 

As a fellow amateur I thought you 
might be interested in an incident that 
happened to me recently. It was a 
fairly fine day except for the band 
conditions. About 2100 GMT I heard 
a 14JJV calling CQ DX on about 
14.204, A perfectly clear frequency 
since everyone was up the band calling 
the KP6 station. I gave the 14 station 
a good clear slow pall. Upon signing 
the initial call to him I was told in the 
rudest way that the frequency was in 
use. I was sworn at in the worst way. 
Not one station identified itself. This 
went on for about three minutes. The 
language was the kind you might use 
on a football field as a line backer. 
Then a W5 very nicely and politely 
asked me to QSY, that the frequency 
was in use for some time and he 
understood that I did not hear the 
KP6 that supposedly was near by. 
What people will do to satisfy their 
ego to work a DX station. 

This was not the end of it. Several 
minutes later I received three obscene 
phone calls from amateurs in the area. 
Two of them I did not recognize their 
voices. But one of them did identify 
himself. He is a member of the 
Northern Illinois DX Association, I 
was sworn at, cussed out, and 
threatened ! His language was worse 
than what a linebacker would use on 
the football field. He was one of the 
guys that cussed me out on 14.204. 
Most of the other guys were members 
of the N.LD.X.A. also. Above all, 
Gary said that all the DX cards I get at 
the ARRL 9th region QSL bureau will 
be TORN UP and then BURNED! He 
also said that I will never get another 
card from the bureau again as long as I 
live. I forgot to say that the ARRL 
9th QSL bureau is run by the 
N.KD.X.A, and I know that one of the 
guys cussed me out that day. He was 

the one that gets alf the cards and 
then distributes them to the letter call 
managers. 



SST T-l RANDOM WIRE ANTENNA TUNER 




All bind opefarmn 400 10 m*i«#»l «m|h mcwf 
any random tangth wir« TOO waif powet 
cjpabiltty Ideal fui pcuMhkt or harm opera 
non. A muir for Fwld Duv Sri* 7 x 4H « 
2 3^8 Built-m neon lun«up indicjipr Guaran 
imd I or 90 days. 

COMPACT - EA&Y TO USE 



onlv 



$24 . 94 



POSTPAID ADD SALES TAX I* CALIF.) 

SST Electronics PO Bo* I Uwndale CA 90260 



How does the possibility of going to hamfests, 
or any gathering of hams and making over $100 
sound to you? For more information on becom- 
ing a local representative for 73 Magazine, write 

Director of Marketing 

73 MAGAZINE 

Peterborough IMH 03458 



OCTOBER 1974 



135 



My main concern Wayne, is how 
the ARRL can entrust a very respon- 
sible type of service to such irrespon- 
sible people, I know I had quite a lot 
of cards at the bureau. But what 
about the 30,000 other amateurs in 
this region that entrust all their cards 
to these people? Any one of their 
cards may be tossed at any time. 
Especially if they don't like you. 

I guess you get the general idea of 
the story. You can throw this away, 

publish it or anything really. But I 
would like to hear your comments if 
you would please. 

Michael A, Krzystyniak (Smith) WB9IJV 

412 Lincoln Street 
Downers Grove 1 L 60S 1 5 

LOG KEEPING 

Good evening, Gents, In response 
to a request from Paul WA5IAT, I 
called the office of Prose Walker at 
the Amateur Division of the FCC 
today. Mr, Walker was on travel, so I 
talked with one of the other gents 
there about the new log keeping regu- 
lations. Before this phone call, from 
what ] had heard and read, I had the 
impression that if one placed a calen- 
dar in the shack and circled the date 
of every day he operated, that would 
suffice for a log under the new regula- 
tions. When I related this to the FCC 
rep, he said that even that interpreta- 
tion was too strict. I will convey to 
each of you what I was told today. I 
can not serve, of course, as the final 
authority for such, but I can see little 
chance of misinterpretation of what 
he told me. 

Fixed and Portable Operations: 

You are required to log only the 
date you place the station in opera- 
tion, and the date you take it out of 
operation. You should also log the 
dates of the beginning and end of any 
long periods of inactivity. In addition, 
this log should contain the call sign 
and signature of the licensee "or" a 
copy of the station license. 

r 

Mobile Operation: 

There are no log requirements 
whatsoever for such operation with 
the exception of "third party" re- 
quirements below. 

Exceptions: 

1. You must stiil log all "third 
party" traffic. This aiso applies to 
mobile operations! 

2. You must still have visitors sign 
the log and enter their call sign. I did 
not get a complete explanation of this 
as to the detail of the log in this case. 
His words were "you must log the 
date and time periods of visitors with 
call sign and signature." 

3. For remote control set-ups like 
repeaters where you have more than 
one controlling station, you must log 
the date and times the control began 
and ceased (each operator must tog 
this for his control period). 

That's the extent of what I learned 
today. 

de Bob K4EID 




RANJIT KAUR 
GURBUX SINGH 



I hope this letter finds you in the 
best of health, I am well and wish you 
the same. I don't know if you remem- 
ber me, but maybe the following will 
refresh you. I am the eldest son of 
Tara Singh XZ2KN of Burma. 

When you were in Rangoon, I had 
asked for a pair of golf shoes and 
some badminton gut and you had sent 
it thru Dr, Charan Singh, 9V1NR of 
Singapore. At that time, I was trying 
to get a visa as an immigrant to USA. 
The official Red Tape was stalling and 
to make matters worse, I was taken 
into protective custody by the 
Government of Burma on 12th July 
1972 and released on 17th October 
1 973. I left Burma by air for Bangkok 
the same day and the next day went 
to Singapore. I was happy to get out 
of Burma and as I had no acquain- 
tances in Singapore, my father told 
me to look up 9VINR and 1 stayed 
with his family while I worked from 
scratch to acquire my visa to USA. 

Dr. Cnaran's daughter, Ranjit, and I 
took a liking to each other (frequency 
response?) and with our parents bless- 
ings, we were married on 10th 
February 1974 at this residence, f left 
for the States exactly a month later. I 
have sponsored Ranjit and she will get 
here by the end of the month. Here is 
one instance where amateur radio has 
brought two families together. And 
believe me, I thank you for it as you 
were instrumental in introducing a 
fellow ham from Singapore to my 
father. I did not even know that he 
had a daughter, Hi! I am enclosing a 
picture of us taken on our wedding 
day. I am working as a technician in 
Springfield for Ford and have rented 
an apartment in Rochester, Illinois. 
My father thinks that our marriage 
would be good publicity for Hams all 
over the world, 

My best wishes to you and hope to 
hear from you sooa 

Gurbux Singh 
Rochester I L 62563 



MURPHY'S 
LAW 



AS IT APPLIES TO SYNTHESIZERS 

General Engineering 

1, Any idea to make it better will 
be preceded by someone else a week 
earlier. 

2. The more simple a design change 
appears, the further its influence will 
extend, 

Specifications 

1. In specifications, Murphy's Law 
supercedes ohm's. 

2. For anybody's cost estimate, 
your cost will exceed the estimate by 
a factor of 3, 

Building and Wiring 

1* Any wire cut to length will be 
too short. 

2. Identical units tested under iden- 
tical conditions will not be ideptical in 
the field, 

3. The availability of a component 
is inversely proportional to the need 
for that componenL 

4. If you need components, you 
will be able to get n-1 parts- 

5. A dropped tool will land where it 
can do the most damage. (Also known 
as the taw of selective gravitation.) 

6. Interchangeable parts won't. 

7. If the first one works, subse- 
quent units will malfunction, 

8. The most delicate component 
will drop, 

9. If a circuit can't fail, it will. 

10. A transistor protected by a 
fast-acting fuse will protect the fuse 
by blowing first, 

11* A self-starting oscillator won't, 

12. A crystal oscillator will oscillate 
at the wrong frequency — if it 
oscillates. 

13. An NPN transistor will be a 
PIMP, 

14. If an obviously defective com- 
ponent is replaced in a synthesizer 
with an intermittent fault, the fault 
will reappear after the unit is 
buttoned up. 

About the author: 

Mr. Edsel Murphy is a victim of his 
own Laws, Destined for a place in the 
engineering Hall of Fame, something 
went wrong. 

In fact, the Law first came to him 
in all its simplicity when his bride-to- 
be informed him of the impending 
birth of an heir to the family fortunes. 
(Reference EEE, Vol 15, No. 8 Aug. 
1968 by D.L. Klipstein) 

Submitted by Leo WA1HSO 



136 



73 MAGAZINE 



Submitted by; 

Michael Kresila 

Box 57 

Marion OH 43302 







1. 
TO. 



ACROSS 

Sudden current or voltage changes in a 

circuit 

Used in the grid circuit of a vacuum 

lube to provide a necessary voltage. 

The unit of luminance. 



1 1 . Unit of magnetic intensity or mag- 
netizing force equal to one gilbert fn 
one centimeter. 

I Z The pitch, duration, or both of a tone 
sensation. 

13. A gfow lamp that produces intense 
flashes of fight when fed with timed 
voltage pulses. 

16. Above. 

1 7, A device used in some mechani 
television systems to modulate a light 
beam with television signals. 

IS, Standard screw-thread base used lor 

electric lamps; 
22. Also called a needle. 

24. A unit of loudness, 

25. Short for address system. 

28. The ease with which an alternating 

current flows in a circuit* 
3D. Breathing device. 
32 Potential difference or voltage. 

34. A cathode-ray tube developed in 
England. 

35. The superposition of one image onto 
another (e.g., in the Formation of an 
interlaced scanning raster). 

36. The positive nucleus of the hydrogen 
atom. 

DOWN 

1. A chemical element used as a rectifier 
layer in metallic rectifiers. 

2. Any system of control performed 
from a distance. 

3. Level. 



7. 
S, 
9. 

14. 



15. 
19. 

20, 
21. 



23. 



24, 



26. 



27. 



29. 

31. 

33. 



Variations of a chemical element, each 
having the same atomic number but 
differing in atomic weight. 
A device that contains and delivers 
power to move a control. 
Eastern Standard Time. Abbr 
A loading. 

The Stationary plates of a variable 
capacitor. 

A number which, when multiplied by 
itself a number of times, equals a given 
number. 

Elementary unit of storage. 
Electrically charged atom or group of 
atoms. 

To stop a flow* 

An alloy wire used in precision wire- 
wound resistors because of its low 
temperature coefficient of resistance. 
The part of a transmitter that trans- 
lates the densities of the elemental 
areas of the subject copy into signal- 
waveform. 

An opening that supports and electri* 
cally connects to vacuum tubes or 
components when they are inserted 
into it. 

The spring fastened around the drum 
to hold the record sheet or copy in 
place. 

A rotalable device on which one or 
more pre tuned circuits are mounted 
for use in all-wave receivers. 
Identical pair. 

An array of antenna elernenis, one 
above the other. 
Negative. Abbr. 



1 




2 




3 






14 


5 




6 




7 




8 








^■9 












lC 














11 


























T2 






^5 


13 














14 


















16 




17 








: 




19 












20 












25 


21 




22 










23 




24 










26 










^M^tM 




28 








2Q 












30 


















32 




33 










• 






























75T 
















36 










■ 



LU 

< 




O 




O 





o 

CO 



OCTOBER 1974 



137 



♦^♦;*:*:#:#:#:#:*:#:#:# 



Caveat Emptor? 



.♦:♦:♦:♦:♦:♦:#:#.♦ 



Price - %2 pe* 25 words tor non -commercial 
ads. SlO per 2 Swords for business ventures No 
display ads or agency discount Include your 
check with order 

Deadline tot ads is the 1st of the month two 
months prior to publication For example 
January 1st is the deadline for ihe March issue 
which will be mailed* on the 10th ol February 

Type copy Phrase and punctuate exactly as 
you wish it to appear No alt capital ads 

We wHI be the judge of suitability of ads. Our 
responsibility for errors extends only 50 print- 
ing a correct ad in a tater issue 

For £1 extra we can maintain a reply box far 
you, 

We cannot check mto each advertiser, so Caveat 
Emptor . . . 

PERSONAL ATTENTION plus the 
best cash deal anywhere is what you 
receive at QUEEN CITY ELEC- 
TRONICS in the heart of the 
Midwest, Queen City carries all major 
brands including Drake, Tempo, 
Kenwood, Yaesu, Swan, Regency, 
Clegg, Standard, ICOM, Genave,, . . 
write or phone us for your equipment 
needs. Queen City Electronics, lnc. r 
7404 Hamilton Avenue, Cincinnati, 
OH 45231 (513) 931-1577. 



TECH MANUALS for govt, surplus 
gear - $6.50 each: R-390/URR, 
R-220/URR, URM-25D, CV- 
591A/URR, CV-278/GR, TRM-1, 
TS*382D/U, TS-497B/URR, TT- 
63A/FGC, URM-32. W3IHD, 7218 
Roanne Drive, Washington DC 20021. 

LEARN DESIGN TECHNIQUES 
Electronics Monthly Newsletter. Digi- 
tal, linear construction projects, de- 
sign theory and procedures. Sample 
copy SI. 00. Valley West, Box 2119 E, 
Sunnyvale CA 94087. 

BUY-SELL-TRADE Write for 
monthly mailer. Give name address 

call letters, Complete stock of major 
brands new and reconditioned equip- 
ment. Call us for best deals. We buy 
Collins, Drake, Swan, etc. SSB and 
FM. Associated Radio, 8012 Conser, 
Overland Park KS 6 6204. 
913-381 5901. 

VERY INTERESTING! Next 5 issues 
$1. "The Ham Trader/' Sycamore II 
60178, (Ask about our "HAM EQUIP 
MENT BUYERS GUIDE 11 covering 
Receivers, transmitters, transceivers, 
amplifiers 1945—74. Indispensable!) 

ELECTRONIC SIRPLIS resistors 
1/4 and 1/2 watt 5t capacitors 10£ 
tube and solid state components. Cat- 
alog 10d SASCO Electronics, 1009 
King St., Alexandria VA 22314. 



FREE: 12 extra crystals of your 
choice with the purchase of a new 
Regency HR-2B at S229. Send 
cashier's check or money order for 
same-day shipment. For equally good 
deals on Collins, Drake, Kenwood, 
Standard, Clegg, Swan, ICOM, 
Genave, Hallicrafters, Tempo, 
Midland, Ten-Tec, Venus Hy-Gain, 
CushCraft, Mosley, and Hustler, write 
to Hoosier Electronics your ham head- 
quarters in the heart of the Midwest. 
Become one of our many happy and 
satisfied customers* Write or call 
today for our low quote and try our 
individual, personal service. Hoosier 
Electronics, R.R. 25 r Box 403, Terre 
Haute IN 47802. (812) 894-2397, 



YOUR SWAP N SELL ads run free in 
TRADIO, a public service publication 
of Wichita Amateur Radio Society 
Box 4391 Wichita Falls TX 76308. 

MOBILE IGNITION shielding gives 

more range, no noise. Everything from 

economical suppression kits to custom 
shielding, literature Estes Engineering, 
543-A West 184 Street, Gardena CA 
90248. 

FOUNDATION for Amateur Radio 
annual hamfest Sunday, October 20, 
1974 at Gaithersburg Maryland Fair- 
grounds. 

MOTOROLA PORTABLES Expert re 

pairs, reasonable prices, fast turn- 
around time. More details and ftat rate 
catalog FREE, Ideal services, 6663 
Industrial Loop, Greendale W( 53129. 

CALL LETTER LICENSE PLATES - 

still being collected by 73 Magazine 
for possible cover use. Please send in 
an old call letter pfate — most 
treasured are out-of-district plates 
such as W2NSD/NH, etc. Got any real 
oldies? 73 Magazine, Peterborough 
NH 03458. 

JIG SAW PUZZLES wanted. If you 
have any old wooden jig saw puzzles 
in your attic — or run across them at 
an auction (they go for 2M usually), 
please keep in mind that Wayne Green 
collects them and might even pay a 
buck a petce for them, c/o 73 Maga- 
zine, Peterborough NH 03458. Wood, 
not cardboard — and complete, 

WANTED: General Class (or higher) 
hams to join 4,500 member Morse 
Telegraph Club, Hundreds of hams 
already belong. Send modest S3 
annual dues (includes subscription to 
great slick paper newspaper "Dots and 
Dashes") to GST A. J. Long, 520 West 
Schwartz Street, Satem IL 62881 for 
membership card and assignment to 
nearest chapter 

TRADE: Collins 390A and manual for 
late model transceiver — write what 
you have George Keys WA6KAA, 
1334 N, Broadway, Santa Maria CA 
93454. 805 925 7755. 



CU 286/FRR 33 - New Collins 1-32 
MHz antenna/receiver tuner coupler 
with autotune circuit for remote oper- 
ation. With schematic and power 
connector, $50. WA1TEJ, 100 
Granite St.. Londonderry NH 03053. 

REGENCY TMR -I6H/L/UHF execu- 
tive scanner, like new, never used 
since unpacked. Covers 2, 6 and 3/4 
meter FM activity. S125 sacrifice. 
WA1TEJ, 100 Granite St, London- 
derry NH 03053. 

AN/ARC-27 — Two complete (fixed 
or mobile) 220 MHz systems: Two 
RT-178/ARC-27 Collins Synthesized 

transceivers (200-399.9 MHz), various 
control boxes, cables, connectors, 
shock mount, blade antenna, spares 
and manual. Units can be inter- 
connected to operate repeat or used as 
mobiles, control stations or U.S. mili- 
tary monitor sets. $200. WA1TEJ, 
100 Granite St., Londonderry NH 
03053. 

WANTED: CV-89A/URA-8A in good 
condition with cabinet (must be work- 
ing) or AN/URA-17 Comparator Con- 
verter Group; brackets for mounting 
CV 89 in 19" rack. Write WA1TEJ, 
100 Granite St., Londonderry NH 
03053. 

FOR SALE: Heath HW101 transceiver 
aligned at factory, HP23B AC Power 
Supply, SB600 Communications 

Speaker, HM102 RF Power meter, all 
in excellent condition, one year old. 
Also Turner 454C SSB Ceramic Micro- 
phone, excellent condition. Best offer 
takes all. Ben Johnson, RRT Box 1 17 
Apt,2,OTallon I L 62269. 

NOW PAYING $2000.00 and up for 
ARC-94/618T A RC-1 02/61 8T. 
$1200.00 and up for ARC-51BX. 
SI 500 and up for 490T-1 antenna 
couplers. We also need these control 
boxes - C-6287/ARC-51BX 
C-6476/ARC 51 BX C 714E 2. We also 
need R-1051 receivers 
RT-662/Grc-106 transceivers. We buy 
all late aircraft and ground radio 
equipment. Also pack radios. We are 
buyers not talkers. Bring your equip- 
ment in, you are paid on the spot. 
Ship it in, you are paid within 24 
hours. We pay all shipping charges. If 
you want the best price for your 
equipment, call us. Call collect if you 
have and want to sell or trade. We also 
sell. What do you need? D&R Elec- 
tronics, R.D.I Box 56, Milton PA 
17847. Phone 717 742-4604. 9:00AM 
-9:00PM. 

AN/FRR 23 (AN/SRR-13) general 
coverage modular receiver with book, 
excellent condition. $100, WA1TEJ, 
100 Granite Street, Londonderry NH 
03053. 

RCA SENIOR VOLTOHMYST- pro- 
fessional grade VTVM, new, never 
used. $50. WA1TEJ, 100 Granite St., 
Londonderry NH 03053. 



138 



73 MAGAZINE 



EQUIPMENT CLOSEOUT 

The following equipment has been in the original cartons or else like new 

purchased by 73 Magazine for test or after a few days of testing in the 73 

has been received in lieu of payment labs, 
for ads. Most gear is either brand new 

MITS 908M Calculator w/p s7case ($143) new • • , $ 79 



* ■ + * 4 i 1 



* * * W 



Vanguard Scaler ~r by 10 - to 200MHz ($120) 

Pickering CW keyboard KB 1 ($265) tested 

Motorola KW 2m amplifier- used . . . . 

Heath I C 2009 calculator-brand new (S92) 

Signal One CX7-A-tested-perfect— like new-fantastic 

Concord video monitor VM-12-tested ($400) • . . *$ 

Concord all channel TV tuner Dem-91 1 ($600) „....$ 

Regency 450 MHz scanner-(S2D0}-like new ........ $ 

Varitronics PA- 50 2m amp ($110) brand new-lOw in 50 Wout . . .$ 

RP tone burst gen-5 freq TB-5—exc ($37.50) . ..« , $ 

Regency HR-6 ($240) six meter lOw xcvr 12ch $ 

Regency ACT-R8H/L Scr ($160) VHF/UHF flchscr receiver $ 129 

Standard SR-C82GMA ($398) Latest model 1 Dw 12ch 2m xcvr .... ..J 329 

Regency HR-ZMS ($319) 2m 15w xcvr with 8ch scanner . .$ 259 

SfiESB450TRC($180)450MHztransverter $ 139 

Regency Pocket scanner 4 channel ACT-P4H ($1211) $ 89 

Cobra 220 MHz Transcerver lOw 12ch (S300) .$255 

Standard 14 U 2m 22ch superfantastic rig, VOX ($510) demo . . . . .S 429 
Pacificom 2m HT— brand new-(S250) $ 1 

All Prices fob: UPS collect 
73 Magazine — Peterborough NH 03458 



* * « * mW #3 

f * • t .O I J*J 

..$ 375 
S 79 

- $1989 

199 
199 
139 
89 
25 
189 



ROCHESTER, NY - Harnfest date for 
1975 - May 31st, Marriott Inn is new 
headquarters. Information? Write 
WNY Hamfest, Box 1388, Rochester 
NY 14603. 

DESIGN ENGINEERS, Our expand 

ing Atlanta based electronics company 
has several opportunities for BSEEsor 
MSEEs Design Engineers to join our 
group dedicated to the design and 
development of satellite communica- 
tions equipment. We are seeking can- 
didates for these positions who are 
hardware oriented engineers with 
background in some of the following 
areas: Solid State Microwave low- 
noise and power amplifiers; Fre- 
quency converters; Analog & Digital 
modems; IF Circuitry; Base band pro- 
cessing circuitry; Frequency sources; 
MIC Techniques. To explore these 
excellent career opportunities, please 
call collect to: Bob Placek or Jim 
Wallace 404-938-2930, Or send 
resume in confidence to: Personnel 
Manager, ScientificAtlanta, Inc., P.O. 
Box 13654, Atlanta, GA 30324. An 
equal opportunity employer. 

REWARD! Ten dollars reward for 
return of 73 Magazine flag lost at 
Dayton. 

REGULATED POWER SUPPLIES 

13.8 volt 3% regulation. 3.5 amp - 
34.95 7 amp 59.95. Also 1, 14, 25 
amp. Meters available. Enterprise 
Electronics, Box 61, Monroe OH 
45050. 

WANTED: Cash for a good automatic 
voltage regulator, also need a trans- 
ceiver, band scanner, antenna rotator, 
transmatch. Albert, 304 East Court 
land, San Antonio TX 78212. 



PERSONAL ATTENTION plus the 
best cash deal anywhere is what you 
receive at QUEEN CITY 
ELECTRONICS in the heart of the 
Midwest. Queen City carries all major 
brands including Drake, Tempo, 
Kenwood, Yaesu, Swan, Regency, 
CI egg, Standard, ICOM r Genave. • . 
write or phone us for your equipment 
needs. Queen City Electronics, Inc., 
7404 Hamilton Avenue, Cincinnati 
OH 45231 {513)931 1577. 

DRAKE: 2B f 2BQ, 2AC. Alt IOmeter 
crystals, plus 5 extra crystals (WWV 
etc.) manual. Excellent condition 
package $175.00. Call Jim W1VYB 
617 922 3850. 

AUTOPATCH — Using your Touch- 
Tone pad, key your transmitter with- 
out holding PT.T. switch. VA to 2 sec 
delay. G-10 glass P.C. board, sche- 
matic, pictorial, and parts list. $2.50 
plus C.O.D. WB6FXF Rick 1613 E. 
Porto la Avenue, Santa Ana CA 92701 
or call 714 836-9363, 

TT 513/FR - Solid-State RTTY non- 
impact teleprinter, accepts all speeds, 
excellent condition with manual and 
connector, $150. WA1TEJ, 100 
Granite Street, Londonderry NH 
03053. 

CANADIANS - We stock a broad line 
of electronic parts, including solid- 
state. Send for free flyer, DARTEK 
ELECTRONICS, Dept. 7, Box 2460, 
Dartmouth, Nova Scotia. 

FM-27B and homebrew power supply 
$325. Clean, used as base station. 
WA2VWM Dave 1420 York Avenue, 
New York NY 10021. 212 734-4135 
(After 1800), 



BUILD a 200MHz frequency counter. 
8 digit LED readout. Drilled boards 
with instructions for 20MHz counter 

S25. 200MHz prescaler option $3.50, 
Manual only $5.00. DAVIS 
ELECTRONICS, 6 W. Oakwood 
Buffalo NY 14214. 

SOLID STATE components, readouts 
and LEDs, Free flyer. DAVIS 
ELECTRONICS, 6 W. Oakwood, 
Buffalo NY 14214. 

FM WIRELESS mike transmitter kit 
$2.00. DAVIS ELECTRONICS, 6 W. 
Oakwood, Buffalo NY 14214. 

2r>0MHz prescaler board. Drilled, with 
instructions $3.50* DAVIS 
ELECTRONICS, 6 W, Oakwood, 
Buffalo NY 14214. 

WANTED: Drake AA-22 2MHz FM 
transmitter receiver amplifier; perfect 
operating condition only. Howard 
Pence, 524 S. Washington, Montpelier 
IN 47359. Phone 317 728-2588. 

VOLUNTEER needed in Orange, 
California area to handle traffic for 
Bible translators. Also need RTTY 
gear; tax deductabie. WA8B HR, 4466 
Burtch, North Street, MI 48049. 

FOR SALE: Thriving 2-way Buisness 
in medium size Midwest market 
$40,000,00 annual Gross. For further 
information write c/o Box J, 73. 

TV-3B/U NAVY portable tube tester, 
good working condition. $25. 
WA1TEJ, 100 Granite St, London- 
derry NH 03053. 



TUBE 
WARRANTY CLAIMS 

Although the price of receiving- 
type tubes is quite low, and a 12AX7 
won't break very many of us, the 
enlightened amateur will check the 
warranty information on his tubes 
carefully. 

Most tubes are guaranteed for two 
years from date of manufacture, with 
a six-month shelf life allowance. If the 
tube gives unsatisfactory service, 
except for burned -out filaments or 
breaks, the manufacturer will 
generally replace the tube. 

At WA6CPP I have had occasion to 
return two tubes to my friendly parts 
house in the past month. Covered by 
the warranty, these were promptly 
and cheerfully replaced, The $6 
saving, while not much, can be 
budgeted for other essential items 
often needed. 

It is a good idea to check the tubes 
on receipt, running them for a week 
or so to see if they are working 
properly. Also, be sure to hang on to 
the invoice the counterman gives you, 
in case there arises a question whether 
you got the tubes there or from the 
supermarket machine* 

. . .WA6CPP 



OCTOBER 1974 



139 




MEMPHIS TENN, OCT 6 

The Mid-South Amateur Radio 
Association is sponsoring the Memphis 
Hamfest on Sunday October 6 at 
State Technical Institute, 140 at 
Macon Rd (Exit 11). Seminars, 
demos, displays, XYL program, prizes, 
flea market, fun. Talk in 3980, 34/94, 
and Army Mars. Trailers and campers 
hookup at Welcome Inn across street. 
Holiday Inn there too. 

SAN DIEGO NOV 1-3 

ARRL SW Division convention — 
Town and Country Hotle — talk in 
34-94, 3900, 7250. $5.50 registration, 
$9.75 banquet. Write Box 82297, San 
Diego CA 92138 for info and p re- 
registration details. 

BERMUDA Oct 13 20 

This is amateur radio week in 
Bermuda. Oct. 16th: annual meeting 
of the Radio Society of Bermuda. Oct 
18th: annual RSGB dinner at Holiday 
Inn, St. Georges honoring the winners 
of the Bermuda contest. Oct. 19-20 
portable operation of VP9Bs in the 
Scout Jamboree. To get a license to 
operate in Bermuda write to the 
Radio Society of Bermuda, Box 275, 
Hamilton Bermuda. Travel and 
lodging should be arranged with your 
local travel agent. 

EL PASO TX OCT 12-13 

Hamfest and swap meet — seminars, 
prizes, flea market. Info: WB5CMB.. 
7772 Gran Quivira, El Paso TX 
79904. 



WINNIPEG MAN. OCT 5-6 

Hamfest "74," International Inn, 
Winnipeg. Reg to VE4RL, Box 352, 
Winnipeg Man. Can. R3C 2H6 $1 ea. 
Dinner and dance Sat. $4 each. Hotel 
$24 couple special. Xmtr hunt, mobile 
contest, homebrew contest XYL 
events, big prizes, auction. 

GAITHERSBURG MD 
OCT 20 

Foundation for Amateur Radio 
annual hamfest at the Gaithersburg 
Fairgrounds. Flea market, exhibits, 
events, many prizes, picnic grounds 
and free parking. For infor write or 
call Bill Miller K4MM, 10919 
Woodfair Road, Fairfax Station, VA 
22039,703 273-0112. 

WEST GHENT NY OCT. 5 

Northeast States 160 Meter Asso- 
ciation annual fall meeting at Kozel's 

West Ghent (near 
market, dinner, prizes, 
Dinner $5.75 ea. — 
reservations: W1JEC, Box 44, West 
Granby CT 06090. 



Restaurant, 
Hudson). Flea 
starts 2 pm. 



QCWA NATIONAL CONVENTION 

Disney World 

October 25-26 - make plans now 
to attend this QCWA National. Write 
W4UKA, 635 SE 19, Ocala FL 32670. 

SO. SIOUX CITY NB, OCT 4-5-6 

The ARRL Midwest Convention 
will be held at the Marina Inn, South 
Sioux City NB sponsored by the 3900 
Club. Theme — tribute to handi- 
capped amateurs. Friday noon start. 
QCWA dinner, portable repeater, 
SSTV, ATV, Amsat demo, QRP 
session, AR RL forum, repeater forum, 
traffic forum, flea market, Mars, ex- 
hibits. $7 reg to W0EQN 3818 5th 
Avenue, Sious City IA 51105. Ban- 
quet $6. 



140 



73 MAGAZINE 



A SIMPLE PULSE 



CIRCUITS, CIRCUITS, CIRCUITS 



GENERATOR USING THE 



SIGNETICS 555 TIMER 



Christer Falkenstrom SM4DZR 

Box 120 

S-660 SO Fagerds 

Sweden 



This puke generator is a very useful tool, 
ft is mainly intended to be used as a variable 
clock when breadboarding or testing digital 
\C systems, especially at low clocking rates. 
Due to the wide range supply voltage 
allowed for the SE/NE555 it can be used 
with RTL, DTU TTL, and HiNiL It uses the 
existing system voltage, anything between 
+4 and +15V. This circuit comprises three 
555 Timers. 

The first 555 Is connected as an astable 
clock. The leading edge of the negative 
output pulse is used to trigger the second 
555. This is connected as a one-shot and 
delivers a positive-going pulse which is used 
as the positive output. The third 555 is 
connected as an inverter to generate the 
negative-going output pulse. This pufse 
appears about 4fi after the positive pulse has 
started. The rise and fall times are about 
100nS. Output currents are 100mA and 
more. With a load of 1 KO between output 
and +V CC the current drawn by the complete 
circuit is 17mA at 5V, and 52mA at I5V. In 
the prototype ten heavily overlapping ranges 
were chosen, mainly depending on the avail- 
ability of 10-way selectors. The following 
table shows the capacitor values and the 

corresponding PRI and PL ranges achieved. 
These values are by no means circuit limita- 
tions, the timing can be extended to minutes 
with suitable capacitors. 



C: 



PRI 



The following circuits have appeared in the reference books t magazines, application 
notes, etc. While we try to reproduce ail of the information that should be needed by an 
experienced construe tor \ readers may want to avail themselves of the original sources for 
peace of mind: 

Readers are requested to pass along any interesting circuits that they discover in 
sources other than US, ham magazines. Circuits should be oriented toward amateur radio 
and experimentation rather than industrial or computer technology. Submit circuit with 
all parts values on it, a very brief explanation of the circuit and any additional parts 
information required, give the source and a note of permission to reprint from the 
copyright holder, If any, and the reward for a published circuit will be a choice of a 13 
book Send your circuits to 73 Circuits Page, 13 Magazine, Peterborough NH 03458. 



3.1 K 




; 




5E/NE 
3 S3 



o 



o I a 



+-fr 



.CKH 



"If 



f 



*}.W 



w CLOCK Q 



CLL 



5E/NE 
BBS 




#— * 



* * 



M.SK 



L&K 



_n_ 



JZ3 



5E/HE 

R 555 



©QNE-SHCJT 



INVCTTER 



JT 

K 



— KesI 

PULSE 
POLARITY 



22 ^LL? J!EL -'I 



1AHTALLM 



AL 



* * 



osc 



-H-I5V 
D 



IM400I 



OUTPUT 



N4O0I 



PULSE REPETITION INTERVAL 



PULSE LENGTH 



*-* 



% 



0M 



* I 

THRESHOLD Q-* 

CONTROL S[ 
VOLTAGE °-f 



PtSCHAHSE 



TaeaFRCK 




G RESET 



OUTPUT 









SUPPLY 
VOLTAGE 




■H 




— -04-I5V 


fVLSE 

GENERATOR 


PUT 




CLOCK 

INPUT 










COM 




^OGNO 











RTL/DTL 
TTL/HiNIL 

SYSTEM 



CONNECTING Tie PULSE GENERATOR TO 

A DIGITAL SYSTEM 



PL 



.0022 /jtF 


70jLtS- 


1 6 mS 


15 fiS 


580 uS 


.0047 ^F 


1 30 fiS - 


3,7 mS 


34 jiS - 


1>3 mS 


.01 ^F 


280 y$ - 


8/1 mS 


71 pS - 


2>8 mS 


,022 jxF 


600 uS - 


17 mS 


165 juS - 


6,6 mS 


.047 ^F 


1 ,4 mS - 


40 mS 


350 juS - 


14 mS 


.1 ^F 


2,8 mS - 


78 mS 


770 juS - 


30 mS 


.22 juF 


6,1 mS- 


172 mS 


1,7 mS - 


67 mS 


.47 jiF 


1 2 mS - 


360 mS 


3,1 mS — 


122mS 


1 pF 


30 mS - 


810mS 


8 mS 


330 mS 


2,2 /iF 


62 mS — 


1,76 S : 


17mS - 


700 mS 



PULSE 
GENERATOR 


+ 






m 




OUT- 
PUT 

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POWER 
SUPPLY 
4-ISV 




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DRWFHG A RELAY 



ANSWER TO PUZZLE 



POIMT "fl' 



C3 $?* 



USEFUL OSCILLATOR 



SI turns on osc. S2 turns it off. Uses are 
many - such as an auto headlight rem inder> 
sidctone oscillator, code osc, square wave 
generator, etc. For auto headlight reminder 
conned 1 to l he dashboard panel lights, 2 to 
the car battery via 52, 3 to ground and 4 to 
the car radio speaker, Voila! Thanks 
W7BBX. 




Ol-QS-AMY IfPN 



SPEAKER-ANY iWPEDflNCE 
ANY SlZf 



•I 



■ CAP 

HATTERY 



I 




DA5HBMR0 
PAW EL LIGHT 
DIMMER 



r3* QflSHBOflftD 
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73 MAGAZINE 



141 



r 



ANOTHER SELECTRONIC SPECIAL 

For This Issue Only 

RADIO RECEIVER R-392/URR 

Freq. Range: 500 KG to 32 MC in 32 bands. 
Types of Signals Received: CW, IV1CW, Voice 
(AMI and Freq. Shift Radio Teletypewriter. 
Type of Tuning:Continuous: Freq, Read Direct- 
ly on Counter^Type Freq. Indicator. Method 
of Calibration: Built-in crystal Calibrator. Cal- 
ibration Points: Every 100 KG, Nominal Input 
Voltage: 28 Volts DC; will operate on an input 
of 25 to 30 V. 
PRICE: $1 95.00 F.O.B. Philadelphia, PA 

Shipping WL SO lbs. (with schematic) 
With schematic, checked and guaranteed. 




We will include with every purchase the follow- 
ing accessories for the above receiver — FREE 

1 Whip Antenna 

1 Speaker 

1 Mike 

1 Set Connecting Cables 

1 Head Set 

1 Telegraph Key 



We have a few of the R-392/URR Receivers that 
need minor repairs, good shape as is, physically 
complete, $125,00 



ADJUSTABLE PRINTED CARD BOX 

For Rack Mount 
5" to 7%" - 16 slides and sockets — includes 
30 double contact position edge connector type 

PRICE $9 95 



MODERN ALUMINUM BENCH RACK CABINET 
1 1 it" H x 18" D x 19" W. 8" panel openings 
w/rubber feet and disappearing handle. 
Lt Blue Price: $7.95 ea. 



Triad transformers F-21A 115 Volts 60 cycles 
6.3 VCT at 10 Amps. Price: $4.95. 



R 508 VHF RECEIVER 

118-148 MHz, part of ARC-60 aircraft radio 
set. Front panel tuning 118-148 MHz, light* 
weight, compact, 5" x 6" x 12". 28 VDC input, 
250V, 50mA, dynamotor. Price: $14.95 



DIGITAL READOUTS SETS 

Make your own counter, frequency meter, 
digital voltmeter, readouts, etc. Includes 6-B 
5031 mixes w/sockets i.6" character height), 1 
transformer, 1 p/s board with socket. 

Price: $12.95, 2/S20.00 

Small B-5031 nixies no board w/socket 4/S5.00 



ANOTHER SPECIAL 
LARGE ALPHA NUMERIC READOUTS 

Two B7971 tubes in sockets, driver transistors 
and components all on one board - can be used 
for clocks, counters, numerous other uses. . , . 

Price: $2.00 a board, 3/$5,00 



Oil Capacitor 
177 UFD - 1000 Volts $10.00 2/$18.00 



VU Volume Level 20 to + 3 $4,95 



SOCKETS 
Sockets for 4 x 150s — 2 sockets with 
chimney, mounted on aluminum chassis $7.00 



MODULE TYPE P/S 
AC irput 95-1 25 VAC-60Hz-1 00 watts. 

+ 1 2VDC3 .375A - 1 2VDC3 3 AMP 

6VDC a .375A 

Regulation 1%. Front panel adj^0%.5 1/8" x 
7 3/8" x 7" p rice: $14 g5 2/$ 25.0Q 



Lighted switches 2 pdt push pole panel mount 
5/8" hold, p rice: $ 1-00 each 6/S5.00 



TRIAD TRANSFORMER 
cycles 6.3V ct at 20 amps. 
4 x 1 50 D 28 volt filament 



- F*22 



115 volts, 60 
$5.95 
$5.95, 2/$ 10. 00 



TOROID INVERTER 

P/S high efficiency, equipped with cooling and for 
continuous duty. Input 27.5V at 5.5 amps, output 
250 VDC at 300 mA, 45 VDC at 1 m A, 1 1 5 VAC 
400 cycle at 30 VA. 3" round by 8 3/4" long. 6 lbs. 



ANOTHER TOROID INVERTER 
Input 27.5 V at 23 amps. Output 1000V at 500 
mA. 4" round x 8>S" long. 8 lbs. Both inverters 
operate on 1 2 VDC one half voltage output. $14.95 



METERS - 1 3/4 square, VA hole mount - 1" 
behind panel. 0-25 mA FS. $2.50 



ADAPTERS BNC to SO-239 



2/$1 .00 



ALL PRICES ARE F.O.B. OUR WAREHOUSE, PHILADELPHIA. PA. ALL MERCHANDISE DE 
SCRIBED ACCURATELY TO THE BEST OF OUR KNOWLEDGE YOUR PURCHASE MONEY RE 
FUNDED IF NOT SATISFIED TERMS ARE CASH MIN. ORDER $5.00 ALL MERCHANDISE 
SUBJECT TO PRIOR SALE RFE - REMOVED FROM EQUIPMENT. 



$£UCr#0A//C$ 



1 206 South Napa Street 

Philadelphia, PA 19146 
215 468 7891 215-468 4645 



142 



73 MAGAZINE 



rule ro&y ate m 9 

international 



M H8S 1 J 



7 ? £ •+ 



* P m r ww 



The Hybrid Analog 

TONE GENERATOR 



MH8913J *1BQQ 



microsystems 

international 



MHS9C* 



DATA and APPLICATION SHEETS FURNISHED WITH OttDER 



t 



mm 



j 



general specifications 

Frequency DrifiH): < ]&% 
Group Amplitude Stability: =25% 

Total Distortion { Harmon jc + InterrnQdulationI: 
< 5% (relative to level of fundamental frequencies) 

typical circuit connection diagram 

jhMrfil 
I * I 



features 



Type*! Rise Tim* to Specified Output and Frequency: 

Frequency selected, power supply switched * 5ms 
2 J Power applied, frequency selector switched < ?ms 
3 J Power applied, frequency within same group 
changed c 2ps 



■ Dual Frequency Capability 

* Standard Telephone Tone-Dial Frequencies: 

Low Group - 697. 770, S52. 941 Hr; High Group 
\2m. 1336, 1477. 1633 Hz 

• Specification Ratings Exceed CCIT7 
Recommendations 



lotALtAD 

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block diagram and pin configuration 

(Top View) 



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dliil ElJ^tnrT%t>n I]-, p#fl Sullen 3*CFrni>(9'* 

on* lr*aw*ime v iter freuj> f« u kn ,n tr>* 

(•"•'•Tien «f j ftmi^lrcr l©n» 



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MHS9L3T CAN BE USED WITH CHOMERICS #£R2l&24 TOUCH TONE KEYBOARD 



HOMERICS3 



FORMATS 
Standard legends are 
black and white set En 
Standard Medium typo. 



©tungKgv TEafgrns keye^a^ 




CALCULATOR FORMATS 



TOUCH TONE FORMATS 



as© 

CDS® 

ESQ 



0©® 
00® 
00® 

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# & 



CODING 

Touch Ton* 12 Key 



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Single PuIb 12 Key 



* a c & c r &hj* l m^ 



Touch Tone 16 Kay 

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Single Pota 16 Kay 



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# of 


Model # 


Price 


Model # 


Price 


Format 


Coding 


Keys 


ER 21622 


7, 15 


ER 21605 


7.70 


Touch tone 


Single pole 


12 


BR 21623 


8.70 


ER 21606 


9.25 


Touch tone 


Touch tone 


12 ! 


ER 21624 


J ♦ i J 


- 


- 


Touch tone 


Direct to MH89 13 


12 | 


- 


- 


ER 21607 


7.70 


Calculator 


1 Single pole 


12 




* 


ER 21608 


11.00 


Calculator 


BCD 


12 


ER 21625 


8.70 


ER 21609 


9.25 


Calculator 


Single pole 


16 


- 


- 


ER 21610 


9.25 


Touch tone 


Single pole 


16 






ER 21611 


11.15 


Touch tone 


Touch tone 


16 



< 



KA ELECTRONIC SALES 

1220 MAJESTY DR DALLAS, TEXA: 




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C214D 634-"7S"7D 
TWX 310-aB190SB 



OCTOBER 1974 



143 




Until October 31 our General 
fantasically LOW prices. 



Electric Progress Line units are going for 




-13N 30 to 
output, with tr 
OCTOBER ONLY 





50 mffilH 
ruotiiit 



.» . r t 








;•:-:■:+:->;* 



* « * *■■#.:-»■: 



'■■■w :.:*:.::■: 



* * • * 



thirty watts 
arly $65.00, For 

• * • • • 5pl30.Uu 






FA/E-16N 30 to 50 
output, with front 
OCTOBER ONLY 



mount accessories. 





» + l»; 



+■ * t * < ■ -*;x*. 



+ + 



•+::o* +. 



SIXTY watts 
00, For 

. . ; . $70.00 




raHgSg 





on 



•■-l. . i-fc-. 











comes in 
should be wor 
order. 





f S.Wlllive a'WHH sen 








|pglil<with 

ViVJi"..', ■.- ■.■.■ \ 

your 

e tun 

lis alone 

your 



v. v. 



Send Check or Money Order to: 

DU PAGE FM INC. P.O. Box 1 Lombard, 

(312) 627-3540 



I. 60148 



TERMS: All items sold as is. If not as represented return for exchange or refund (our option) 
shipping charged prepaid within 5 days of receipt. Illinois residents must add 5% sales tax. 
Personal checks must clear before shipment. All items sent shipping charges collect unless 
otherwise agreed. Accessories do not include crystals, relay or antennas. 



144 



73 MAGAZINE 



w 



. 






MOTOROLA 2 m FM 



• 25 or 1 watt models with 1 -watt low power switch 

• Installation of receive frequency crystal provides receive, simplex transmit 
and repeater transmit (—600 kHz) 

• Best intermod and adjacent channel refection available 

• 12-channel capability 

• Optional tone burst encoder — mounts internally 

• Optional secondary transmit offset frequency kit 

• Snap -in mounting tray 

• Typical Motorola quality and performance 



o&- 



25 WATT TRANSCEIVER 

-600 kHz OFFSET CRYSTAL 

12 CRYSTALS (YOUR CHOICE} 

LARS EN 5/8 WAVE MOBILE ANTENNA 

CHOICE OF 

(1) TONE BURST ENCODER KIT 



$495.00 

13.00 

108.00 

29.00 



(2| SECONDARY XMIT OFFSET KIT 40.00 



j£68SrO(r 



FORA LIMITED TIME. 

(financing available) 



ED JUGE ELECTRONICS, INC. 



3850 S. FREEWAY 
FT. WORTH TX 76110 



11181 HARRY HINESBLVD 
DALLAS TX 75229 



OCTOBER 1974 



145 



I 

1 



« 



* 



ft. 

■H i 










YOUR HAM & PARTS 
HEADQUARTERS 



Attain 



fn'V 

* V "I -* 

r ■* */ 

-■35 



GALAXY^GT 550A 





m 







* 

■ * 



<s 




S& 












• Crystals supplied for 3.5 to 4.0, 7.0 to 7.5, 14,0 to 
14.5, 21,0 to 21-5, 28.0 to 29.0 MHz. Optional xtals 
may be installed for other 10 meter coverage. 

• Plate Power Input: 550 watts PEP on SSB - 360 watts 

The 18AVT/WB Is constructed of extra heavy ?jt| on cw and RTTY [50% duty cycle). 
duty, taper swaged, seamless aircraft aluminum ;jg;J 

with full circumference, corrosion resistant j^jg 

Receiver Selectivity: 2.1 kHz with 1.8 shape factor for 
z sharp selectivity with optional CW filter. 

• Freq. Stability: Within 10 Hz during any 30 minute 
warm-up period, less than 100 Hz in any 15 minute 
warm-up period, not more than 100 Hz with a plus or 

the 1 8A VT/WB just stands up $p 



• Power Output: 300 watts PEP (nominal) on SSB ■ 180 
watts on CW and RTTY. 



S3 



compression clamps at all tubing joints, This f?$ "ood eiV rfnn u 

:-Y , * * * i i . , „ ?; J bob Of JUL) H 

*?,d antenna is so rigid, so rugged . - - that its ful >:&M 



. . . that its full 'grj* 

25' height may be mounted using only a 12" ||Si 

double grip mast bracket , , , no guy wires, no ^jj* 

extra support **■- 10A WTAWD ="--*-** — ■ KSi 



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<"ush 



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am 



ROHN 



® 







Ottatf£&aea&& 



ascom 

TOWERS 




the antenna 
specialists co. 



t> € 



V- 

J-- 



ALL 73 and ARRL PUBLICATIONS ALWAYS IN STOCK 






■ ■ 



I 



491 Riverside, Medford, Mass. 02155 

(617-396-5550) 



146 



73 MAGAZINE 




-* 



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MS 

A. 
S? 

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1 



MODEL 4220 RECEIVER 
STEREO 2 + QUADRADI AL 4 

Affordable 4-channel by Marantz. The 4220 is the most 
economical of all Marantz Quadradial receivers. But it doesn't 
compromise quality or craftsmanship. For example, the 4220 
features SQ, with logic for decoding SQ records and tapes. 
And you don't have to worry about replacing your stereo 
collection. An ambience circuit is included which gives many 
stereo recordings the full 4-channel effect of a live perform- 
ance. There's still plenty of power to fill a room with that 
dynamic Marantz sound. Over 20 Watts per channel for 
stereo and more than 8 Watts per channel for Quadradial. 
Gyro-Touch tuning, 4-channel balance controls and loudness 
compensation switch are all standard. 



MARANTZ 



5 

2245 
2220 
4220 



Se 



ndQ SL 



Card for °» ote 



/ 



SPEAKERS - MARANTZ, PIONEER, RECTILINEAR 



TT 






ft'- 
$-1 



ty 

i »T 

■ « ■ * 

* <■■ 

« -» 












491 Riverside, Medford, Mass. 02155 

(617 396-5550) 



OCTOBER 1974 



147 



CHARGE IT 
ON 



THE INTERBANK CARD 



CALL 
FREE 



TOLL 

FREE 

NUMBER 

(Continental 48 States) 

800 
325-3636 

MO CUSTOMERS CALL 

314-993-6060 

COLLECT 



CHARGE IT 
ON 




BANKAMERICARD 



Wmmm MW 



CALL 



TRADE 



TRADE 



NEW 



CALL 
HAM RADIO CENTER 



USED 



(9 A.M.-5 P.M. Central, Closed Sun. & Mon.) 

FOR 
A SQUARE DEAL 



ON 








DRAKE 
TEMPO/ONE 

TEN-TEC 

CLEGG 

STANDARD 








YAESU 

SWAN 

COLLINS 

KENWOOD 

REGENCY 



We carry all major brands and a large 
stock of used reconditioned equipment 

HAM RADIO CENTER INC. 



8342 OLIVE BL. 



ST. LOUIS, MO 63132 



148 



73 MAGAZINE 



THE SOLID STATE SURPLUS OCTOBER AD 



Dear Customer, 

This month we're going to answer a question that many people ask: what 
exactly is a "surplus" IC? 

An IC may be considered surplus for a variety of reasons, none of which need to 
reflect on the quality of the part. 

One large source of surplus parts is companies that go out of business , and need 
to sell off inventory to minimize their losses. Another source is semi-conductor 
manufacturers with just too much stock, due perhaps to overproduction or 
overestimation of demand. In this case, the manufacturer is better off selling the 
stock at a lower but still profitable price to the surplus dealer. 

Some parts are also considered "defective/* No doubt this raises fears in the 
mind of the buyer, but consider what an IC manufacturer calls defective, An IC 
classified as "cosmetically defective" means that it is a perfect functioning unit, but 
with a flaw in the looks that makes resale at full price difficult (for example, 
scratches or marks in the case from handling). Another source for "reject" ICs is 
high-reliability programs, where extremely critical parameters must be met. A 
company may manufacture a load of parts, but only sell the ones with the absolute 
tightest specs. What happens to the rest? They're considered prime units for resale; 
unless you're building a moon rocket, they are. 

At Solid State Surplus, we try to be as careful as possible when deciding which 
lots of parts to buy. But being careful isn't really enough, so we test every single 
one (no, not spot checks, each one) and make sure that it meets consumer and 
industrial grade parameters. If it does, it stays. If it doesn't, it usually goes back to 
the factory and gets any precious metals reclaimed, 

So much for the discussion. Now for the nitty-gritty sales pitch. 

WeVe got linears. . .741, 747, 558 op amps. . .the 3900 current-differencing, 
single-supply quad op amp. . .a choice of regulators: the 309 (5 or more volts out, 
blow-out proof, current-limiting, I amp @ 5 volts) and the 723 (less power, more 
precision). . ,a choice of comparators, too, either the 339 quad single-supply 
comparator, or the industry favorite 311; fast, and it can handle a fairly heavy load 
(relay etc.). . .the 555 timer, as versatile a building block as the op amp. * *and two 
unusual op amps, the 4250 micro power type, and the 531 fast slew op amp. 

But that's not all. We are happy to announce the addition of the CD40I 6f an 
IC containing 4 independent electronic switches using CMOS technology, A coritrol 
voltage determines whether the switch is open or closed. In some cases, you can 
even use them linearly, like a voltage-con trolled attenuator. Anyway, they're good 
to have around; get a few and find out. 

If you've talked to anyone who's ordered from us lately, you'll find we still (1) 
ship airmail whenever possible, even with the rate increases! 2) give fast turnaround, 
24-48 hrs. ARCM(3) don't backorder — we give you back your check if we ain't got 
it. _ 



LM309 5V 1A 
LM723D regulator 
LM311 comparator 
LM339 quad comp. 
LM555 timer 
CD401 6 quad switch 
LM741 minidip op amp 
LM747 dip dual 741 
LMI558 mini dip dual 
LM3900 quad op amp 
LM4250 micropower amp 
NE531 hi slew amp 



We'll have something new for you 
next month, . . 



SOLID STATE SURPLUS 
BOX 255 

MONTE RIO CA 95462 



Above material is guaranteed functional, retested material. User satisfaction 
guaranteed for hobby and experimental applications. 



OCTOBER 1974 



149 



INTERNATIONAL ELECTRONICS UNLIMITED 



DIGITAL INTEGRATED CIRCUITS 





Ea. 




Ea 




Ea. 


7400 S .1 


7447 * 


n/is 


74141 41 


7401 


.19 


744fl 


1.15 


74145 


1.15 


7402 


,19 


7450 


.24 


74150 


1.09 


7403 


,1 C J 


7451 


.27 


74151 


.69 


7404 


.22 


7453 


.27 


74153 


1,29 


7405 


.22 


7454 


.39 


74154 


1.59 


7406 


.39 


7460 


.19 


74155 


1.19 


7407 


39 


7464 


.39 


74156 


1.29 


740 B 


.25 


7465 


,39 


74157 


1.29 


7409 


.25 


7472 


,36 


74161 


1.39 


7410 


,19 


7473 


.43 


74163 


1.59 


7411 


.29 


7474 


.43 


74164 


1.89 


7413 


.79 


7475 


.75 


74165 


1.89 


7415 


M 


7476 


.47 


74166 


1.65 


7416 


.39 


74B3 


1.11 


74173 


1.65 


7417 


.39 


7465 


139 


74176 


1.09 


7420 


.19 


7486 


.44 


74177 


.99 


7422 


.29 


7489 


2.75 


74180 


1.09 


7423 


.35 


7490 


.76 


74181 


3.65 


7425 


.39 


7491 


1.29 


74182 


.89 


7426 


.29 


7492 


.79 


741 B4 


2.69 


7427 


.35 


7493 


.79 


74165 


2.I9 


7430 


.22 


7494 


M9 


74190 


1.59 


7432 


.29 


7495 


.89 


74191 


1.59 


7437 


,45 


7496 


.89 


74192 


1,49 


7430 


.39 


74100 


1.65 


74193 


1.39 


7440 


.19 


74105 


.49 


74194 


1.39 


7441 


1.09 


74107 


,49 


74195 


♦99 


7442 


.99 


74121 


.57 


74196 


1.09 


7443 


.99 


74122 


.53 


74197 


,99 


7444 


1,10 


74123 


.99 


74198 


2.19 


7445 


,99 


74125 


.69 


74199 


2.19 


7446 


,99 


74126 


.79 


74200 


7.95 


IOW 


POWI 


ER TTL 








74L00 


.33 


74L51 


33 


74L90 


1.69 


74L02 


.33 


74L55 


.33 


74L91 


1.45 


74LD3 


.33 


74L71 


33 


74L93 


1.69 


74UJ4 


.33 


74L72 


.49 


74L95 


1.69 


74106 


,33 


74173 


AS 


74L9B 


2.79 


74L10 


.33 


74L74 


.69 


74L164 


2.79 


74L20 


.33 


74176 


.79 


74 LI 65 


2.79 


74L30 


,33 


74L85 


1.25 






74L42 


1.69 


74L86 


.69 






HIGH 


SPEEI 


TTL 








74H0O 


.33 


74H21 


.33 


74H55 


,39 


74H01 


.33 


74H22 


.33 


74H60 


.39 


74H04 


J3 


74H30 


.33 


74H61 


,39 


74H0S 


.33 


74H40 


.33 


74H62 


.39 


74H10 


.33 


74H50 


.33 


74H72 


.49 


74H11 


.33 


74H52 


-33 


74H74 


.59 


74H20 


.33 


74H53 


.39 


74H76 


.59 


8000 


SERIES 


I TTL 








A091 


.59 


an 4 


1.69 


8811 


.69 


8092 


.59 


8220 


1.69 


B812 


1.10 


8095 


1.39 


8230 


2,59 


8822 


2,59 


B121 


.89 


8520 


1.29 


8830 


2.59 


0123 


1 59 


BS51 


lifiS 


8831 


2,59 


8130 


2.19 


8552 


2.49 


6836 


.49 


8200 


2,59 


S554 


2.49 


8880 


1.33 


6210 


3.49 


8810 


.79 






9DO0 


SERIE! 


5 TTL 








90(12 


.39 


| 9309 


.89 


9601 


.99 


9301 


1.T4 


9312 


,B9 


9602 


.89 


Please inec-fy dj 


i\a shr.-fk 


rt»quiT*rf 


with o r dcr 


. Add 


J.5C 0C r 


dale ihe 


*t for lie mi 


priced fa 


ii than Si 00 each. 



CMOS 



74C0U 


,39 


74C74 1.15 


74CI62 3,25 


74CG2 


.55 


74C76 1.70 


74CT63 3.25 


74C04 


.75 


74C107 1,50 


74C1G4 3.50 


74C08 


.75 


74C151 2.90 


74C173 2,90 


74C10 


,65 


74C154 3.50 


74CI95 3,00 


74C20 


,65 


74C157 2.19 


80C95 1.50 


74C42 ; 


2.15 


74C160 3.25 


80C97 1.50 


74C73 


1.55 


74C161 3.25 






4000 


SERIES RCA EC 


JUIVALENT 


CD4001 


.55 


CD4013 1.20 


CD4023 .55 


CD40D9 


.85 


CD4016 1.25 


CD4025 .55 


CD401Q 


.85 


CD4017 2.95 


CD4027 1.35 


CD4011 


.55 


CD4019 1.35 


CD4030 ,95 


CD4012 


.55 


CD4022 2.75 


CD4035 2.85 


MEMORIES 



1101 256 bit RAM M05 

1103 1024 bit RAM MOS 

5260 1024 bit RAM Low Power 

7489 64 bit RAM TTL 

B223 Programmable ROM 



10% OFF ON ORDERS OVER $25.00 



LOGIC PROBE KIT 

• Ten nano/sec capability 

• Checks TTL & DTL logic 

• Dual slope memory 

• Internal 5V regulator 

Kit is complete with all necessary 
corn pone tits, case, probe, complete 



instructions and logic chart. 



$13.95 



TRANSISTOR GRAB BAG 

PNPSt NPN 

Yield 50% + Good 

Good for use as segment drivers 30/ Si .00 



CALCULATOR CHIPS 



50CI1 LSI (40- Pin J Add, iub|r. r mult. & div.. 12-dip. 

Data ^upplic.-d with Chip S3 .95 ea 

Data onlv — Refundable with purchase 1.1)0 

5U\y'2 LSI similar to 5001 exc. des. far battery 

operated - Data supplied wlrh chip 7.95 ea. 

Data onlv — Refundable with purchase 1.00 

5005 LSI (20 pin! Full 4 funct. mem. 12-diH- dlspl. & 

calc. 7 s*^. mltplx. uutp. Data suppf. w/chtp 0,45 ea. 

Data qnly — Refundable wiih purchas* 1.00 

WM5736 IB Pin. 6-diR., add, subtr., muii., dlv. 3.95m, 



DIGITAL CLOCK CHIPS 



POWER SUPPLY SPLITTER KIT 

* Ground reference for positive & negative 

output from single supply — any DC source to 20V 

* Balanced output adjustment 

* 1 amp-current capability with sink 

* increase usefulness of your power supply 
Complete with all components & instructions $4.95 

18 PIN CALCULATOR KIT 

* MM 5736 18 PIN Calc. Chip four function 6 Digit 

* A pair of 3-in-1 PAKS (6 digit) LED NSN 33 

* One 75492 HEX Digit driver 

Schematic and instructions included. You supply 
switches keyboard arid battery for complete calculator. 

$9.95 



LINEAR INTEGRATED CIRCUITS 



inn 
301 
JO! 
JU4 

105 
30? 

IfW 

3D9H 

109 K 

J10 

111 

"519 

320 

324 

339 

MOT 



TOS i 

mini~DIP. TO-5 

TO S 

TO-5 

TO*5 

MINt-DIP, TO-5 

MINUDIP 



Cos V Ren (<yp?r 723 1 

H< performance AMP 

V tillage follower 

Nusattve Voltage R.pruL 

PmiLiwc Voltage RegLjI. 

Op AMP tSLCrer 741 > 

Micro Power Op Amp 

S V ttctu later 200 mi 

5 V 1A Regulator 

Voltaic Foltawtir Op Amp TO-5 

Hi perf. Volt, Com parti. h*<Nt-DIP r TO-5 

Hi-Speed Dual Comparlr. 

Hl'K Res- 5,2, 1^2. IS 

Quad Op Amp 

Quad Cornp.-ir.i1qr 

Pm. Volt. Rfl£. 

! | v ^a V- 1 2 V- 1 5 V~1 flV^4 V) 

ACC/Scjuckh AMPl 



TO-5 
JO-3 



DIP 

DIP 
Q1P 



MM 5311 28-pm any readum S-dlR. BCD mux 
with spet;. iheet 



9.95 ea. 



MM 5312 2 1-pin any readout 4 di^it Ipps output 

BCD mui with spec sheet 6.9S ta. 



MM *i313 28-pin any readout h digit Ippa 

BCD must with sppe. sheet 



7.95 da. 



MM S3 14 24-pin t-ED-lncandescent readout mux 

6-difril with appt. sheet 8.95 ea. 

MM 5316 40-pffl fturm. af^rm set snooze aSarm-ttmer 

12 or 24-hr. qperat, with spec, sheet 12^5 ea, 



MyiOB 

MV5D 

MV5D2D 

ML4 



MAN1 

MAM2 

MAN3A 

MAN3M 

MAN4 

MANS 

MAN7 

MANS 

DL707 



MCD2 
MCT2 



LED$ 



Viiible red TO 18 

Asial leads micro-mini dome .25 ea. 
Jumbo clear dome visible red ,35 64- 

Infra red {invisible? dilf. dnrn^ 



DISPLAYS 



Red, 7 seg,, ,270" ! 

Red alpha numeric, .32" 

Red, 7 s*g., ,127" In hne leads 

R«d r 7 Seft., ,127" staggered leads 

Red, 7 ieg.j .19^' 

Creert, 7 seg,, ,270" 

Red, 7 seg. r .270" 

Yeflow, 7 seg., .170" 

.75" high direct viewing LED 

Red, 7 seg., .3" 



OPTO ISOLATORS 



.25 ea. 

5/1,00 

371.00 

60 ea. 



.SO ea. 
.95 ea. 
.79 ea, 
.15 ea, 
.15 ea. 
.95 ea, 
.39 h 

.65 ea. 

.15 ea. 



"3900 

7524 

7525 

7534 

7535 

flO.10 

75451 

75^-2 

75453 

75451 

75492 



AF-tf StTip-duteclor 
AMy^M/SSfl Strip 

Po*. Vott- ReRulatOr 
2W Stereo amp 
2 Wall Atidio Amp 
.fAV Audio amp 
low-Nrjiid Dual Prp^Amp 
LoW'Nqi?e Dual Pre*Arnp 
Prec. Voltage ReK^^tor 
Timer 
BF-IF AMP 
OpRrational AM PL 
Dual Different. Compar. 
Voltage Regulator 
Dual Hi Peri Op AMP 
Comp. Op AMP 
Dual 741 Op Amp 
Freg- Ad|. 741 
Stereo Prc-Amp 
FM Mulpx Stereo Demnd 
FM Mulpx Stere-o "Demod 
Dual Comp. Op. Amp, 
Dual LM 211 Volt. Comp. 
TV-FM Sound System 
FM Det.-LMTR & Audio 

Pre- Amp 
Quad Amplifier 
Predion Timer 
Core Mem Sense AMPL 
Core Mem S*n?e AMPL 
Core Mem Senie Amp 
Core Mem Settle Amp 
Function Cenrratnr 
Dual Peripheral Driver 
Dual Peripheral Driver 
i3SH Dual Periph. Driver 
Quad. seg. drivrr ior 
LED readout 
Hex diR.il driver 



TQ-J20 

TO-5 or DIP 

DIP 

DIP 

MINI-DIP 

DIP 

DIP 

M EMI -DIP 

DIP 

DIP 

DIP 

MINI-DIP 

MINI-DIP 

TO-5 of DIP 

DIP 

DIP 

DIP 

Ml Mi -OIF, TO-5 

TO-5 or DIP 

MiNI-DIP 

DJP 

DIP 

DIP 

MtNUDIP 

DIP 

DIP 

DIP 

DIP 

DIP 

DIP 

DIP 

DIP 

DIP 

PIP 

MINI-DIP 

MiNI DIP 

MiNLOtP 

DIP 

DIP 



79 ea. 

.32 ea. 

.79 ea, 

-H9 ea, 

.SS pi. 

.35 ea. 

1-lOea. 

1,1 Oea, 

1,^5 ea, 

1,19 e» r 

1.05 ea. 

1.29 ea. 

1 .35 ea, 

1.95 ea. 

1.69 ea. 

1.9S ea. 
1.15 es- 

.7d ea. 
3.25 ea. 

,59 ea. 
2.6$ ea 
l.29*a. 
1,25 ea, 
1.79 ea. 
3.79 ea. 

.79 e*. 

,99 ea. 

.45 ea. 

.29 ea. 

-29 e*- 

,59 ea. 
1.19 ea, 

.35 ea, 

.79 ea. 

-39 ea- 

.89 ea. 
I,l9ea 

8* ea. 

fc9 ea. 
1.95ea. 

.69 ea. 

.79 ea. 

,59 ea. 

65 ea- 
1.69 ea, 

.89 ea, 
2.59 ea. 
1.15 ea. 
4 95 ea, 

.39 ea, 

.39 ea. 

39 ea. 
1.55 ea. 

1.69 ea. 



Diodes $1 09 ea. 

Transistor .69 ea. 



PHASE LOCKED LOOPS 



>60 Phase Locked Loop DIP 

>61 Phase locked Loop DIP 

\hl Phase Locked Loop DIP 

65 Phase Locked Loop DIP 

66 Fundi on Generator MINI DIP 

67 Tone Generator MlhJI-DIP 



Pleat? Specify whuh data shpels are required with Order. 
Add 5.50 per data >.Vd lur m.-mb pnt:ed less than Sl,0t> 
each, 



TRANSISTOR SPECIAL 



Hi Voltage Power Transistor! — Prime Quality 
Typically 40 Beta al 50 MH*. 1GW, 1A max TO*5 

NPN 400 VOLT $2,43 ea. With combined 

NPN MO VOLT 1.20 ea- total of 100 

NPN 200 VOLT ,75 ea. irans — 15% Off 



: C3E3 



1408) 6G9-a773 



All items are new, unused surplus part! — tested functfonaL Satisfaction 
is guaranteed. Shipment will be mode via first class mail — postage 
paid — in U-S., Canada and Mexico within three dayi from receipt of 
order. Minimum order $5.00. California residents add sales tax. 

INTERNATIONAL ELECTRONICS UNLIMITED 

P.O. BOX 1708 MONTEREY, CALIF. 93940 USA 



ADD A DIGITAL CLOCK TO YOUR SHACK 



6 DIGIT CLOCK KIT 

Contains — MM531 3-6 MAN7 — M\ digit interface 
IC'sand all components needed 
less pwr xfmr and case . . 



S27.9S 



4 DIGIT CLOCK KIT 

Contains — MM5312 — 4 MAN7 — all digit interface 
IC's a^d all components needed 
less pwr xfmr and case 



S22.95 



150 



73 MAGAZINE 




7-SEGMENT READOUT 



19-PIN SIP 



n Three digits with right-hand decimal 
b Plugs into DIP sockets 
o Similar to (LITRONIX) 0L337 
b Magnified digit approximately .1" 
a Cathode for each digit 
a Segments are parallel for multiple 
operation r " 

C irt UA . ( ■BAfHB MEW 

n 5 - 10 HA per segment v 

EACH $3.00 4 {12 Digits) $11,00 



RCAnumitron^ 

ttfT 



Ij^ »-t-i rl»*fi»»«.«*««v ^ * u* 



SPECIAL: 5 FOR $20.00 

DR2010 



Potter & Brumfield 

TYPE KHP RELAY 4 PDT 3A 
CONTACTS 

24 VDC (650 

coil}.,* .$1.50 

120 VAC (10,5 MA 
coil}.,.* 1,75 




Power Supply special! 

723 DIP variable regulator 
chip \-km f 4- or - output % 150 
HA I0A with external pass trans- 
istor — With diagrams for many 
appl f cat tons. 

EACH.... $1.00 10 FOR $8,95 



CT5005 CALCULATOR 

This calculator chip has a full four- 
function memory, which is controlled 
by four keys, +M (adds entr<- into 
memory), -M (subtracts entry from 
memory), CM (clear memory, without 
clearing rest of registers), BM (read 
memory or use as entry) . 
12-Digit display and calcu- 
late 
Fixed decimal at 0, l t 2, 

3 f 4, ar 5 
Leading zero suppression 
/-Segment multiplexed output 
True credit sign display 
Single 28-pin chip 

CHIP AND DATA*. ....... ,OKLY $14.95 

DATA ONLY (Refundable) ■•,.,. ■ 1.00 



5001 CALCULATOR 

40-Pin calculator chip will add, sub- 
tract, multiply, and divide, 12-Digit 
display and calculate. Chain calcula- 
tions. True credit balance sign out- 
put. Automatic over-flow indication . 
Fixed decimal point at 1, 2, 3, or 4. 
Leading zero suppression i 
data supplied with chip. 

CHIP AMD DATA ONLY 

DATA ONLY (Refundable)..,. 
5002 LOW POWER CHIP AND DATA., 12-95 

"All tCs =re new and fully-tested; 
leads are plated with gold or solder. 
Orders for 55 or more will be shipped 
prepaid. Add 35c for handling and 
postage for smaller orders; residents 
of California add sales tax. 1C or- 
ders are shipped within 2 workdays- 
kits are shipped within 10 days of 



Complete 

$9.95 
1.00 



CTpL SPECIAL: 

Complementary Trans istor Log ic 
This logic family is unique in 
that both KPN and PMP transis- 
tors are combined in the same 
package. Unlike TTL and DTL , 
the outputs are current sour- 
ces ( Tn the high state ) as 
well as sinking current In the 
low state. Those are brand new 
units, some of which are mis- 
marked with DTL numbers, 

CTL 9956 dual 2-in- 
put AND buffer 
CTL 9953 2-2-3 input 
AND/OR gate 
CTL 9952 dual 2- In- 
put NOR gate 

Data supplied; all parts are 

dual -In-l ine. 




MIX On HATCH 



5 FOR $1,00 



LEDs 



HV50 red emitting 
10-4 ma @ 2V 



receipt of order. 
C.G,D.s (phone in) 

MAIL ORDERS : 
P, 0, Box J 
Carmichael* 
95608 



$10,00 minimum on 



CA 



4811 Myrtle Ave. 
Sacramento, CA 
(916) 3 3^-2161 

MOtfEY_ BACK_GUARANTSE_Ofl ALL^ GQODSt 

SEND FOR FREE FLYER LISTING 100 's OF 
HONEY-SAVING BARGAINS! 

BflBMLOn 




MV5024 red TG-1& 
high dome 




HV10B visible red 

5-7 nta @ 2V 



S .20 
10 FOR 1.25 



$ .35 
10 FOR 2.95 



$ .30 
10 FOR 2,50 



CMOS 

CD4001 $ ,75 74C20 .75 
CD4002 ,75 74C160 3.25 




RECTIFIERS 

VAR0 FULL-WAVE BRIDGES 
V5447 2A 400V 
V5647 2A 600V 



$ .90 

1.10 





3-AmpPower 

Marked Epoxy Axial Package 



FRV PRICE 
100....*$ .10 

200 15 

400..,,, .18 
600 23 



FRV PRICE 
800.,...$ .30 
1000..., .40 

1200 50 

1500 65 



C: 




r-- 
i 

'-J 



;.> 



MAN 1 

7-Se gm en t, 0-9 plus 
letters. Snaps in 14- 
pi n DIP socket or Mo- 
lex. Operates with IC 
vol tage r eq u i r eme n t s . 
Long operating life* 
ONLY $3 .25 



7400 


% ,25 


74H0O 


.35 


7401 


.20 


74H01 


.35 


7402 


.35 


7403 


.30 


7404 


.28 


74H04 


.35 


7405 


.28 


7406 


.70 


7408 


.35 


74H08 


.35 


7410 


.25 


74H11 


,35 


7413 


1.25 


7417 


,40 


7420 


.25 


74L20 


.:E 


74H20 


4 J3 


74H22 


* -J* fej 


7430 


.25 


74H30 


.35 


74L30 


,40 


7440 


.25 


74H40 


* j j 


7441 


1.25 


7442 


1,20 


7446 


1,75 


7447 


1.50 


7448 


1,50 



74L51 
74H51 
7453 



$ .30 
35 
20 



7554" 
74L54 
74L55 



7460 

74L71 

7472 



7*172" 

7473 

74L73 



7474 

74H74 

7475 



I 



7576" 
74L78 

7480 
75S3~ 
7489 
7490 



1 
I 



7493 
7495 



1 

1 



74L95 
74107 
74121 



25 
35 
35 



20 
30 
40 



50 
60 
75 



65 
80 
40 



60 
80 
65 



00 
00 
20 



90 
15 
15 



2.00 

.70 

1.25 



7?T5T 
74193 

74195 



2.30 
1.50 

1.00 



7450 

74H50 

7451 

7400 



.25 
.25 

Seri 



DIP 



HRS10 Rect. 



50V 



1A 



.10 



Special 811: Hex Inverter 

TTL DIP Hex Inverter; pin interchangeable 
with SK 7404, Farts are brand new and are 
branded Signet ics and marked "fill." 

EACH $ .30 

10 FOR 2,50 

100 F0R f . , f 23,00 
1000 FOR.. . 220.00 



Data 
Sheet 
Supplied 



?r 



811 




ii' 'ii 1 



letters 3 MAN 3 
Right-hand decimal point. 
Flat-pack type case. Long 
operating life. tC vol- 
tage requirements. Ideal 
for pocket calculators! 




EACH 

10 OR MORE 



$1,25 
1.00 



{WAIN 4 Seven-segment t 0-9 plus let- 
ters. Right-hand decimal point. Snaps in 
14-pin DIP socket or Molex. IC voltage re- 
quirements. Ideal for desk or pocket calcu- 
lators! a ^ ^-i ^ ■>> 
EACH $2,75 



TEtt OR MORE 2.50 EACHi 



LZSo 



CTT5 1 " 



yyy 



CD-2 Counter Kit 

This kit provides a highly sophisticated 
display section module for clocks, counters, 
or other numerical display needs. The unit 
is .8'* vide and 4 3/8" long. A single 5-volt 
power source powers both the ICs and the 
display tube. It can attain typical count 
rates of up to 30 KHz and also hag a lamp 
test, causing all 7 segments to light. Kit 
includes a 2-sided (with plated thru holes) 
fiberglass printed circuit board, a 7490, a 
7475, a 7447, a DR 2010 RCA Humitron display 
tube, complete instructions, and enough 
Molex pins for the ICs , * NOTE: boards can 
be supplied in a single panel of up to 10 
digits (with all interconnects); therefore, 
when ordering, please specify whether you 
want them in single panels or in one multi- 
ple digit board. Not specifying will result 
in shipping delay* 

complete: kit, only 511,95 
fully-assembled 

UNIT $15.00 
Boards supplied separately g $2.50 per digit. 




* • • # 



. . . ■ 



* ■ * • 



* * * , 



LIN EARS 

NE54Q 70-Hatt power driver amp_. 

HE555 Precision timer 

NE560 Phase lock loop DIP* 

NE561 Phase lock loop DIP 

ME 565 Phase lock loop TO-5. 

NE566 Function generator T0-5.*, 

NE567 Tone decoder MINI DIP. 

NE567 Tone decoder TO-5 

NE5S58 Dual 741 op amp MINI DIP.. 

709 Popular Op Amp DIP ,, 

710 Voltage comparator DIP 

711 Dual comparator DIP..- 

723 Precision voltage regulator DIP 

739 Low noise op amp DIP unmarked,. 

741 Op amp T0-5/MINI DIP 

747 Dual 741 op amp DIP. 

748 Op Amp T0-5 * .... . 

CA3018 Z Isolated transistors and a Da 

ton-connected transistor pair,, 
CA3026 Dual differential amp 
CA3045 5 NPN transistor array... 

LM100 Positive DC regulator T0-5 

LH105 Voltage regulator,,, .....,, 

LM302 Dp amp voltage follower T0-5*., 
LM308 Op Amp T0-5 * » ...,.,.*.«•*•• • • * i 

LM309H 5V 200 HA power supply T0-5 

LM309K 5V 1A power supply module T0-3, 

LM311 Comparator T0-5 

LH370 AGC amplifier.. 

LM380 2-Uatt Audio Amp 

LM1595 4-Quadrant multiplier 
MC1536T Op Amp. ...**.,..,... 



. * . • 



. . < 



- » - » 



,,*♦.*.. 



. » . ■ 



* » , . » 



.$2.00 

, 1.50 

, 3.2$ 

. 3.25 

, 3.25 

, 4.00 

. 4,00 

. 3.00 

. 1.00 

. .45 

. .75 

. ,40 

. 1.00 

* 1.00 

. 1.00 
. 1.00 
rling- 
. 1. 00 
1.00 
1.00 
1.00 
1.25 
1 , 25 
2,00 
LOO 
2.00 
1.75 
2,00 
1.75 
2.00 
2.00 




008A MINICOMPUTER KIT 
8008 CPU, 1024 x 8 bit memory; memory is ex- 
pandable. Kit includes manual with schematic & 
programming suggestions, wire-wrap board & wiring 
list, & power supply parts. $375.00 

MANUAL ONLY: $25.00 

"THE CUBE" Fully assembled subaudible tone 
generator for small hand-held or portable FM 
radio, 9—6 volts; no moving parts; set anywhere 
between 98 & 240 Hz with a trim resistor. 



.5" x .6" x ,7" 



$ 19.95 



Set on frequency by the factory, $5.00 extra. 



TTL 



008A-K ASCII KEYBOARD INPUT KIT 

Includes keys, px. board, ICs, power supply, in- 
structions, schematic; Intended to interface ONLY 
with our 008A Minicomputer Kit. $50.00 

PS 25—1 to 25v 1a lab type power supply with 
adjustable current limiting; remote sensing & re- 
mote programming for voltage & current. Instruc- 
tions included. All parts except chassis & meter(s). 
Kit of parts with schematic $14.95 

PS 5—1 5v 1a regulated power supply kit with px, 
board & instructions. Board measured 2" x 6"; 
completed kit is 2" high. Transformer has internal 
rf. shield $ 8.00 



7400 $ . 


25 


7485 : 


$1.40 


7401 


25 


7486 


.50 


7402 


25 


7489 


3.25 


7403 


25 


7490 


1.00 


7404 


30 


7492 


1.00 


7405 


30 


7493 


1.00 


7406 


50 


7495 


1.00 


7407 


50 


7496 


1.00 


7408 


30 


74107 


.60 


7409 


.30 


74121 


.60 


7410 


.25 


74122 


.60 


7411 


.30 


74123 


1.10 


7413 


.90 


74125 


.65 


7416 


.50 


74126 


.65 


7417 


.50 


74141 


1.25 


7420 


.25 


74150 


2.50 


7430 


.25 


74151 


1.10 


7432 


.30 


74153 


1.40 


7437 


.50 


74154 


1.70 


7438 


.50 


74157 


1.40 


7440 


.25 


74161 


1.90 


7442 1 


.10 


74163 


1.90 


7446 1 


.45 


74164 


2.00 


7447 1 


»*+o 


74165 


2.00 


7448 1 


.45 


74166 


2.00 


7450 


.25 


74174 


2.20 


7451 


.25 


74175 


2.20 


7453 


, *LZ} 


74176 


1.60 


7454 


.25 


74177 


1.60 


7473 


.50 


74181 


4.50 


7474 


.50 


74192 


1.75 


7475 1 


.00 


74193 


1.50 


7476 


.65 


74 1 95 


1.15 


7483 1 


.25 


74200 


9.00 



TRANSISTORS 

NPN TO— 18 gen. purpose silicon 
PNP TO— 18 gen. purpose silicon 
2N2222 (NPN} TO-18 
2N2907 (PNP) TO-18 

JUNCTION FETs, TO-18 case 

N-CHANNEL: SIMILAR TO: 

NJF10 

NJF11 

NJF12 

NJF13 

NJF14 

P-CHANNEL: 

PJF11 

PJF14 



1-9 


10+ 


$ .15 


$ .10 


.15 


.10 


.25 


.20 


.25 


.20 



2N4416, MPF102 3/$ 1.00 
2N4091-93 4/$1.00 



2N4338-41 

2N3089 

2N4221-22 

2N 3382-86 
2N2608 



4/$ 1.00 
3/$1.00 
4/$ 1.00 

4/$ 1.00 
4/$1 .00 



All FETs come with data sheets. 



r 



NEW - GOOD 



PLASTIC TRANSISTORS 



TO— 92 general purpose NPN & PNP transistors, 
beta > 1 00, breakdown > 40v 
$ .08 each $5.95/100 

Specify type and quantity. 



WIRE WRAP SOCKETS 

14 pin $ .55 

16 pin .65 

24 pin 1.30 

28 pin 1.40 

40 pin 1.85 
wire-wrap socket pins 

$ .05 $4/100 



LED PACKS 

LED 10R — Ten discrete red lens 
LEDs, various MV5020 types $1.50 

LED 10C — Ten discrete clear lens 
LEDs, various MV5020 types $1.50 

Application note included. 



RGS ELECTRONICS 
3650 Charles St., Suite K • Santa Clara, CA 95050 • (408) 247-0158 

We sell many ICs and components not listed in this ad. Send a stamp for our free flyer. TERMS OF 
SALE: All orders prepaid; we pay postage. $1.00 handling charge on orders under $10.00. California 
residents please include sales tax. Please include name, address and zip code on all orders and flyer 
requests. 

DISCOUNTS: 10% OFF ORDERS OVER $25.00; 20% OFF ORDERS OVER $250.00. 



152 



73 MAGAZINE 



IF YOU CAN SOLDER, YOU CAN 
BUILD YOUR OWN 

Clock/Calendar 



has available a 



mm sirAirg svsitsims, one 

CLOCK/CALENDAR kit containing over 120 separate electrical 
components. 



The clear, simplified instructions include step by 
step construction procedures and ample illustrations 
which will quickly take you through construction of 
this versatile Clock/Calendar. 

THE KIT FEATURES: 

* DISPLAY OF DATE WITH MONTH AND DAY 
displays month and day automatically, through 
year, except for February 29. 

* DISPLAY OF TIME ON 12 HOUR CYCLE hours 
and minutes displayed with A.M. and P.M. 
indicators. 

* A 24 HOUR ALARM OPTION this also includes a 
snooze button which delays alarm an additional 10 
minutes* 

* A 9 HOUR 59 MINUTE TIMING OPTION - this 
allows operation of any pluggable 600 watt, 120 
volt, 5 amp, 60 Hz electrical device such as a radio, 
room light, stereo or coffee pot. 

* EASILY VISIBLE SPERRY® DISPLAY - this 
display is highly visible in a well lighted room. 

An attractive case may be fabricated of wood, 
plexiglas, metal or whatever you feel would make an 
appropriate show-case for your finished kit, 

TO ORDER: 




PLEASE NOTE: These kits do not include cases. 

This kit when completed is a sophisticated device 
which offers many additional features due to its 
flexibility, here are two examples of what can be 

done with this device: 

I.You may set the timer to play your radio for 15 
minutes at bedtime, then the alarm allows you the 
option of waking up to the radio in the morning all 
automatically. 

2. You may set the alarm to later start an appliance 
which will operate for the duration of the setting 
on the timer. 



Order Number 01-12241 - BASIC CLOCK - This kit does not include the 24 hour alarm option or the 9 hour 59 
minute appliance timer option. Price 



... 4 • 



. 1 * fr • 



..' * . • ■* . * # • * * . .4>*t£3.*30. 



Order Number 02-12241 - COMPLETE CLOCK <■ This kit includes all available options. Price . 



. . ■ . 




$01 J .D STATS SYSTEMS, INC. 



SEND YOUR ORDERS TO: 
SOLID STATE SYTEMS, INC. 
P. O. BOX 617 
COLUMBIA, MISSOURI 65201 

OR PHONE (TOLL FREE) 
800-325-2981 - 800 325-2983 



. . .$65.00 




mtsWtfttfQt 



OCTOBER 1974 



153 




COMMUNICATIONS 



UNLIMITED 




Charlie 11 Gretchen |1||| Sammy 

..-,. r --_-._ llYir . i 1 V « 1 (. ■ _' _"_'V_ m'-m}.^^. 




SPECIALISTS IN CCTV, VTR's, FM COMMUNICATIONS 



Toledo 

SB-23 - 9 mile exit 
1MB-23 - Barker Road 
Main Street 



FUST 



exit - 1 block to 



Store: 9519 Main WH, Ml 

Hours — Noon — 6pm Tue — Sat ES 

Closed some Saturdays 

313-449-4367 




We sell M-Tech, Midland, Larson, A/S, 
Hitachi, Motorola, Dak, Ampex and 
many others 



i.w-in.; 



J \CKSON 




COMMUNICATION!* 
UNI I Ml HO 



WIN I (SOU 



US 23 



TOLEDO 



WE SERVICE 




Ampex, IVC, Sony, Panasonic, 
Shibaden, Norelco and others 
VTR's and CCTV Equipment 

We are an independent sales and service company. Our product loyalty 
is from experience not sales franchise. Qualified, unbiased. 

Consultation service available for video systems large and small. 





BILL GODBOUT ELECTRO 
BOX 2673, OAKLAND AIRPORT, CA 94614 



THOSE WHO HAVE BOUGHT THE 
8008 PROCESSOR FROM US OR 
RGS OR CYBERTRONICS WHO 
ARE INTERESTED IN SHARING 
HAROWARD AND SOFTWARE 
PLEASE SEND FULL NAME AND 
ADDRESS - AND WE WILL PRE- 
PARE A MAILING LIST AND 
SEND IT TO ALL WHO HAVE 
SENT IN NAMES AND 
ADDRESSES. 



8008 PROCESSOR 8 bit on a chip . $50.00 



21 G21 02/2602 N CHAN Bit static RAM. 
SPECIAL FOR THIS MONTH ONLY $15.00 

TTL SPECIAL 74175 Quad Latch $1.10 

MOS DYNAMIC MEMORY 1 x 1024 bit MM5260 $5.00 

LINEAR SPECIAL 741 Mini Dip op amp 10/$3.50 

LM 309K 5V 1A REG $1.75 

LM 320K NEG Reg available in 5V 12V & 15V $2.25 

LM 340K POS Reg available in 6V, 8V, 12V, 15V, 24V $2.25 

4194 TK adjustable dual tracking reg T066 $3.90 

4195 TK dual tracking reg +15V T066 $3.40 



ICs, most I IL& LINEAR in 


stock - 


- Send stamp for FREE 


catalog 




CMOS DIGITAL 














74C00 


.60 


CD4011 


.55 


CD4042 


2.95 


555 


.85 


74C02 


.60 


CD4012 


.55 


CD 4044 


2.95 


556 


1.60 


74C04 


.85 


CD4013 


1.10 


CD 4049 


1.10 


723T 

723D 


.95 
.75 


74C10 


.60 


CD4014 


4.00 


CD4050 


1.10 


74C20 


.60 


CD4015 


4.00 


CD4116 


1.25 


74C73 


1.65 


CD 40 16 


1.10 


■ <■ H ■ ^P* A «*^ 




741M 


.45 


74C74 


1.25 


CD4017 


3.20 


LINEAR 




741T 


.50 


74C76 


1.75 


CD4018 


3.25 


LM301M 


.45 


747D 


.75 


74C107 


1.75 


CD4019 


1.25 


LM311M 


.95 


748M 


.50 


74C151 


3,30 


CD4020 


3.50 


LM318 


1.75 


1595 


1.50 


74C160 


3.25 


CD4021 


4.00 


LM339 


1.50 


1596 


1.75 


74C161 


3.25 


CD4023 


.55 


LM370 


1.25 


CA3028 


.75 


74C162 


3.25 


CD4024 


2.75 


LM371 


1.25 


CA3065 


.75 


74C163 


3.25 


CD4025 


.55 


LM372 


1.25 


CA3086 


.45 


74C195 


3.15 


CD4027 


1.50 


LM374 


2.00 


3900 


.65 


CD4001 


.55 


CD4029 


6.00 


LM380 


1.65 


4136 


1.95 


CD4002 


.55 


CD4030 


.55 


LM381 


1.75 


4250T 


2.25 


CD 4008 


4.00 


CD4035 


2.50 


LM382 


1.75 


5556IV1 


1.50 


CD4009 


.75 


CD4037 


2.95 


LM399 


1.75 


5558 


.75 


CD4010 


.75 


CD4040 


5.00 











ALL ITEMS IN STOCK and will be shipped within 24 working hours of receipt of order! 

Include 50d postage and handling on orders under $10.00 

Sorry, NO C.O.D.'s. CALIFORNIA RESIDENTS ADD sales tax. 



OCTOBER 1974 



155 




TWO METER F.M. PORTABLE 

See p. 16 for New Product Review 

CRYSTAL SOCKETS INCLUDED! 
IMPROVED TRANSMIT AUDIO! 
UP TO 6 KC DEVIATION! 
.35 uV SENSITIVITY OR 
BETTER! 

.25 SQUELCH SENSITIVITY! 
IMPROVED INSTRUCTION 
MANUAL! 

F.C.C. TYPE APPROVAL PEND- 
ING! 



KIT ONLY $129.95 COMPLETE less batteries AND for a limited 
time only we will furnish ONE SET OF CRYSTALS FREE! Your 
choice of 94-94; 52-52; or 34-94. 




IT'S AN EVEN BETTER BUY NOW !!!!!! 

ACCESSORIES: 

"Rubber Duckie" Antenna (BNC Connectors) $12.95 

Nicad Batterie Charger $ 4.95 

Sealed 1 2V Nicad Battery Pack $29.95 

Please include S1.00 for Shipping and Handling — N.Y.S. residents add sales tax 

" HF ENGINEERING" 

- DIV. of BROWNIAN ELECTRONICS CORP. - 

320 WATER ST. POB 1921 BINGHAMTON, NY 13902 607 723 9574 



156 



73 MAGAZINE 



Come Face to Face 
wjtMhefacts iii ^ 

IC-21 A . - * 24 channel capability, with 7 channels supplied. It's fvtOSFET front end 
provide* better than 0,4uv sensitivity ai 20 db quieting. 5 HELICAL FILTERS virtual!) 
eliminate iniermoduiahoit. Built in AC jiiJ £>C power supplies. Modular construction, of 
course. Many other features make the IC-21 a greai two meter transceiver. The IC-21 A is 
capable of using our new digital VFO« 




...andch 




ICOM 



1C-22 . . , 22 channel capacity, with 5 sup- 
plied. Solid state T R switching, and an extra 
large speaker. All the great quality features 
that label it as one of the truly fine ICOM 
transceivers. 10 /I wan power saving option. 
Trimmer caps on all 22 channels tor both 
transmit and receive, plus a built in 
discriminator jack to let you get on and slay on 
frequency. 

The IC-3PA is a regulated DC power supply 
lor all the 1NOUL mobile transceivers. Use it 
with your IC-230 Foi base operation* It's 
compter el > regulated and gives you art 
indication of iCs operating condition; normal. 
excessive current, or if the protection circuit is 
working. These are shown through the use of 
eye catching indicator lamps. There is also a 
built in speaker in the cabinet. 




ICOM 






Distributed by 

ICOM WEST, INC. 
Suite 232 - BkJij II 
3G0 I20lh Ave N.E 
Bettevue. VJasii. 98005 
J6) 454-2470 



Dealership* A vtiljifrla - 

ICOM EAST D>v. ACS Inc. 
Suite &0T 

13777 N Genua) Expwv 
Dallas, Texas. 7523 1 

1214} 235-0479 




OCTOBER 1974 



157 



CALCULATOR KIT 



Kit contains NORTEC calculator chip 4024,21 
driver transistors, 8 LED's, 7 segment readout 
by EXITON. 3 LED for overflow, low btry, over- 
range, a keyboard by FLEX KEY. All this $45 
value for only $16.50 2 for $27 



BASIC CLOCK KIT 

We furnish clock chip CT7001 and 4 first line 
LED readouts .3 inch hgt. You furnish the misc. 
minor parts, A $35 value for , $19.95 



COLUMBIA 4 CHANNEL SQ 

Solid state SQ 4 channel adapter, 2 amps built 
in. Decodes 4 channel or synthesizes 4 channel. 

$35.00 



LED READOUTS 5/$1.00! 

The price is not a mistake. We have some hobby 
variety with some segments out. Ukinbuyem 
for as low as 5 for $1 ,00 



LIQUID CRYSTAL WATCH 

Build a wrist watch or desk clock with this liquid 
crystal display. Recently written up in several 
magazines. Display with special socket reads 
hours and minutes $15 2 for $25 



UNDERWATER LISTENING 

Brand new by OLIN. Use it for a swim pool mon- 
itor-alarm, use it on lake or ocean listening to 
underwater noises, fish, etc, Complete with hy- 
drophone, 50 ft. mike cable, speaker-amplifier 
console. Operates from 115 volts AC or 15 volt 



dry cells. 12 lbs 



*• + ■!■■■ I I IFIl + rillllllltl-ritP 



£25 

lllbihi m ■■■■■■*-■"■■ ^^ <^m V 



CALCULATOR CHIPS 

5001 LSI (40 pin) Add, subtract, 
divide 12 digit. With data ........ 

Data alone 



multiply 

$6.95 

50 cents 



PHOTO STROBE 

For use with most Instamatic cameras. With 
nicad battery and built-in charger. Never buy 
flash cubes again. $9.95 



AM-FM RADIO 

For console installation, w/face plate, no 
knobs. Stereo amplifiers for tape or turnable 
playback. $15.00 

Pair of matching speakers w/xfmrs for above 

$5.00 



CALCULATOR CHASSIS 



CMOS 4814 HEX INVERTER 

CMOS HEX INVERTER, dual inline package. 318 
volt range, dual diode protection against static 
charge. Dielectrically isolated complimentary 
MOS, $L00 each 12 for $1000 



DUAL 16 BIT MEMORY 

Dual 16 bit memory, serial MOS by Philco TO-5 
case, brand new with 2 page specs. 

#PLR 532 $1.00 each $10/12 



AM-FM RADIO $5.50 

Due to the West Coast ship strike they came in 
too late for the customer. Now it's your 
bargain. Use it as is or build it into your own 
cabinet, desk. waK r etc. All built, ready to use 
with AC supply. To make it portable all you do 
is power it with a couple of "D" cells. Fully 
assembled solid state chassis with AC power 
supply, less speakers. Covers full AM as well as 
FM broadcast. The price . , . an astounding 
meager $5.50 



FLEX-KEY KEYBOARD FOR POCKET CAL- 
CULATORS $1.50 



Fully assembled pocket calculator chassis with 
calculator chip. Uses LED readouts not includ- 
ed. $5,00 



ELECTRIC SIREN $10.00 

Brand new, operate 6 or 12 volts dc. Just the 
thing to protect car or boat. Used also as 
burglar or fire alarm in house & camp, Kinda 
scarce, but we found some. While they last 

$12 each, 2/S20.00 



SOLAR ENERGY 

Electricity for free from the sun. An exciting 
experimental device. Instructions included 
show how to make a solar energy bank for 
higher voltages and/or current, also how to 
make a solar operated radio receiver. 

Giant cell 2" diameter - $1,50 
Large cell 1 3/4" - $1.25 
Medium cell 1" diameter - $1.00 
Rectangular 3/4 x VA" - $.75 

Any six for the price of 5 . ♦ ; 



POWER AMP XFMR 380 WATT 

115 volt input, 64 VCT 6 amp output. 

$1 1 .95 each, 2/S22, 5/$50 



BOOKSHELF SPEAKERS 

Completely finished, 9 x 12x5 inches. 16 
ohm, with extension cord. $15 a pair. 



Postage extra on above. MESHNA P0 Bx 62 E. Lynn Mass. 01904 

^ 96-page catalog FREE ! 



73 MAGAZINE 



THREE QUARTER 
INCH DIGITS 

BY OPCOA 

3 for St 3. 



An 



y Color 




*^"1 



t**^ 



t^Yn 



0.7 character 
O to 9 



*teo 

GHECftf 
YELLOW 



_^ Inflation 

ECONOMY 



7 Segment* C 

30 mils 



Order by type 

number 



D 



Type 
SLA-3H 

SLA 4H« 
SLA. 13 
SLA-14* 
SLA 2 3 
SLA 24* 
•Plu* or Minus 



Color 
RED 
RED 
GREEN 
GREEN 
YELLOW 
YELLOW 

one 



CRYSTAL OSCILLATOR 

Rare buy of ihesse popular 
precision module thai are 
used by hams, clock en- 
thusiasts, hobbyists By 
Monitor, Type 8 SO. Fred: 
4.000 Mil*. Accuracy to 
.001, Requires 5VDC. Gen- 
erates a square wave on 
output. Size: IV* x 1 x 
1 ,„" 



$4.95 



Type 

G SN7400 
SN740I 

BSN7402 
SW7403 
5N7404 
Q SM740S 
O SN7406 
Q SW7407 
Q SN7 408 
Q SN7409 
Q SN741Q 

S5N7411 
SW7412 
D SN7413 
Q SN7414 
D SN7415 
G SM7416 
D SN74I7 
U SM74 20 
D SN7421 
G 5N7423 
a SN7423 
Q SN7425 
D SN742S 
D SN7427 



Safe w*i*er fcv 
$.19 



.24 



.27 
.24 
.79 
.48 



.27 



D SN7430 
D 5*7432 
D 5N7437 
D SN7438 
D SH7440 
O SN744X 
D SN7 442 
n SN7443 
O SN7444 
d SN7445 
D SN7446 
5N7447 
SN744S 

SSN74SO 
SN7431 
Q SN7453 
D SN7454 
_. SN74SS 
D SN74SO 
D SN7441 
a 5N7462 
□ SN74S4 
3 SN74S5 
If SN7470 
J SN747I 



tri>fr nirnhfr* Sjirr i 
24 



IC PRICES 



Buy 10 15% 



.45 
,49 



.42 
.52 

.39 
.91 



1.19 

1.02 

102 

1,02 

1,09 

1. 19 

1.19 

1.19 

.27 

.28 

,28 

.39 






.26 



,39 

.39 
.49 



D SN7472 

BSN7473 
5N7474 
SN7475 
D SK7476 

U SN7478 .79 

G SN7480 .89 

SN7481 1.25 

D SN7482 ,99 

Q 5N74B3 1.19 

Q SN748S 2.50 

a SN7486 49 

fl SM7489 3.19 

D 5N7490 1,19 

a SN7491 i^j5 

Q SN7492 .»« 

D 5N7493 .99 

SSN7494 1,05 

SN7495 ,99 

D SN7496 .99 

Q SN74100 1.S5 

SN74104 1,25 

SN74105 .95 

SN74106 .95 Q 



□ 

a 

Q 

a 

n 

a 

a 

a 

a 

a 

a 

Q 



• Factory Marked 

D SN74107 
□ 5N74108 
Q SN74112 
O SN74113 
d SH74H4 
D SN74121 

Q SN74122 
Q SN74123 

SN74125 

SN74126 

SN74139 

SN74140 

SN74141 

SN74145 

5N7414S 

SN741S0 

SN74151 

5N74153 

SN74154 

SW74155 

5N7415G 

SN741S7 

SN7415S 

SN7 4 160 



Buy 100 - — 



Tjk« 



.49 
.95 
.95 
.95 
.95 
.49 
,55 
1.09 
.65 
.89 
1.25 
2,50 
1.19 
1.19 
2.95 
1-19 
.99 
1.39 
1.89 
1.29 i 
1,45 ! 
1.45 
1.4S 
1.85 



v\ 



Tr\ 



n 5.95 

WATT STEREO 
AUDIO AMP 



- 



The factory "snipped" most of the cables to this com- 
pact 8 watt stereo unit with aluminum escutcheon 
plate, |t*« easy to use because we have all the cables 
marked ready to use. With power supply 115 vac 3 
controls. LEFT and RIGHT VOIA'ME controls for two 
speakers for balonrinjg and center TONE control. With 
knobs. 7 x 3*/a x 3 Vs. Hookup spec sheets. 



CLOCK CHIPS 
ON A "DIP" 

QMM5311 6 'digit 
MM5312 4 digit 
UMM5313 6 digit 
JWM5314 6 digit 
OMM5316 4- dig it 
_ MM5316A 



IK L«»W 

94.95 

28- Pin . , . .$7.77 
24 -Pin ... 7.77 
28-Pln 7.77 
24-Pin . 7,77 
40-Pin A|arm9.95 
minu.s Alarm 4.95 




D SN74161 
SN74163 
O SN74164 
□ SN74165 
Q SN7 4 168 
D SN74173 
SN74174 
SN74175 
5N74178 
SM74177 
SM74180 
SN74181 
SN74182 
SN74195 
SN74187 ; 
SN74192 : 
SN74193 ; 
U SN74194 j 
5N74195 \ 
O 5N74196 1 
D SN74197 1 
a SN74I98 2 
Q 5N74199 2 
O SN74200 9 



a 

c 

c 
c 
n 
a 

a 



a 



WITH DATA SHEETS 



iuy Any 3 
Take 10% 

Ott count! 



INTEGRATED 

CIRCUIT SOCKETS 

Si* Pi* t 
14-Pin. 



D 
D 



14 
16 



D18 
—1TO 

a s - 

Pin t 
Pin, 



DIP 5,45! 

Stdp Mount 1.00 

Pin. DIP 50 

5* 8 or 10-Pifij. .29 
Pi«» {Mini DIP) .39| 

Wire Wrap . 
Wire Wrap 



69< 



PROFESSIONAL 

8 TRACK 

TAPE 
TRANSPORT 



Si- io for 



4"- 



^^ 



•z^ 



7r 



expensive home 
player system 



tape 
with 



Same type unit found in the mom 
players. It's a Complete B-trank 

BUILT-IN PKEAMP — juat plug into any stereo ampli- 
fier isee some of our low-priced units K Excellent 
rephtcement umL, or you t;an design your own high- 
quality atereo tape .system. It's the type you insert a 
cartridge to turn-on deck, then enjoy up to 80 minutes 
of non-stop, non*rr?|)i>at Ktort«o. Itamuve cartridge and 
pJuyer "shuts ofl" automatically. HuiLt-in output con- 
trols in preamp. Features: 4 PftCNJHAM INDICATOR 
LIGJJTS. automatic or manual program change, plays 
your car tapea at home, WOW- FREE precision fan- 
cooled motor, which operates off I 15 Vac, Requires 
external 12Vdc supply, for the electronics. With 
diagrams. 



S A N KEN HYBRID S ViKffr *JS" » ^U 

AUDIO POWER AMPS g IJlJSsSI It £.11 

L'scd extensively in hi-fi systems, tape decks, FM lun- 
era. reconl players, stereo components, musical instru- 
ments, P. A., etc. All amplifiers, fiat within J - db from 
hz in lfl0 t 00ft\ Each unii proper^ heat-^inked t with 
heavy-duty connecting tie lag connect jons. Sinjclt-- 
endfd pu&hpull output. Power supply required 2lVIn 
Output to S ohms, Order by Stock No, 



m^^ 



HIGH POWER 
TRANSISTOR 
WITH HEAT SINK 



j for %y o 91.49 

llemoi rd frtirn new equi|^ 
menlf JnrhideM jiupulur 
2N17 4 diirirkuuh Lmn*i>- 
tur TO-Jlfl^ gi-rmnnium, 



I*NF. 150 watta, VCBt) 
HQ\\ 15 amjiH, -111 hft-. f tl r 
iffmiion r hjjch [inner trjin -.- 
milters, etr. Mounted nn 
heal sink 5 x a 1 ^ x iV*** 



D 



15.95 



D Only 



fl-Watt Stereo Amplifier, 

fi- Track Tape Transport 

and hook-ups both. ^15f*™5 



dRmt H3©s8@s 



n 

Vour C ho tea 

Silo. 95 



*•**■ 



EPOXY 

FULL 

WAVE 



P1V 2 Amp 

50 G S.69 

100 79 

SILICON 400 c ll% 

BRIDGE eoo O 1.35 

[RECTIFIERS aoo ] i.S9 

CTada: 2 «mn l * M ° ^ 7 * 



6 Amp 

a *.88 

.99 
! 1.25 
D 1-30 
□ 1-75 
n 1-95 
D 3.25 

t/ltf ^q 



POLY PAKS 

BLUE RIBBON 

INCLUDES 



20- Years of Business 
INTEGRITY 



BASIC KIT J^l - — includes case, all-function Flex Kev 
Keyboard, Cal Tech CTS002 calculator chip, 9-digh 
Ante* Lfct* dinplay with huilt-on individual magnifiers, 
plus hheeta. 

BASIC KIT #2 — same aa Basic #1 except calculator 
chip is National S-dtglt MM5735. 

BASIC KIT £3 - — sume as Basic #1 except calculator 
chip is National ti -digit MM5736 and 754 32, 



PRECISION 
CRYSTAL 



DOnly 

$1.95 



20-Yeirs ot Money -Back 
GUARANTEES 



Excellent time base and 
other uses. 5.000 MHz. 
Type H6U case. 



19'Yeirt of Economy! 
LOWEST PRICES! 

48-HR. SERVICE 



12 DIGIT BASIC 34 — Key parts include: CT5001 
chip, 4-3 diffit readouts, factory etched PC board, case, 
carrying caae, 2-resiator networks* decimal switch. 
Wild Rover Keyboard with 0N-0FF switch diagrams. 
Sale $24.95 

12* DIGIT BASIC "MEMORY" KIT £5 Key part* 

for 4 -memory calculator. Caae with "slight touch key- 
board*** CTR005 memory chip, 6 MAN 3X ON-OFF 
switch, book, (*extend key allows 12 digits), pc 
boards ), 919.9ft 



j on an 



— r fisj 



D 

$2.50 

**£" THRU 
S METER 

Indicates: to i-5 
Plastic caac 



"ULTRA BRITE* 
XCITRON LEDS 
$2*50 D9-pc. krt 

Qnt? of Poly Pak^ exclusive 
ultra-hrite offers m "dull" 
prices. Ktt includes: 3 RKl.JS. 
A V KEENS. 3 YELLOWS, 
each including JUMBOS 
MEDIUM and MICROS. 



Output 

r, t 0V 
6.3V 

1 2. over 

ls.nvcr 

150.0^ 
7.0 V 



Sal* 

# .120A $1.00 

3 A 2.95 

JA 2.95 

2A 2.50 

fiOMA. 

1A* 2.95 



*Ni*ie tube tranaf, 



FILAMENT 
TRANSFORMERS 

Input all 115/60 cycles. 
Open frame and raetaJ en- 
cased. 



6 -digits 



- . l 



i#f 



Money -Back 
GUARANTEE 
on all Items 



6 DIGIT 

KRONOS 

CLOCK 

Uilnft MAN - 3 S 

jz*S^- Complete 

, $29.95 



OPCOA SLA-1 

REFLECTIVE 

LED READOUT 

"Red 1 * :_ 

L.95 



SCRS! TRIACS! 
QUADRACS! 

SAME PRICE 
SALE! 

19- Amp Power 
Tab Plastic Units 



D KIT 



7-flegiTient, 
Character 0.33" 



PRV 

] SO 
100 

] 200 

] 3CM) 

] 400 

] 900 

SOO 



■la 
.79 



Made by SHURE. Type 
CM1 tfl. Originally used for 
Raytheon Marine eqpt. Ex- 
cellent fidelity, sensitivity. 
Gray molded plastic case, 
with red push-to- talk but- 
ton. With heavy-duty flexi- 
ble cord, mounting socket 
on back. 




SHIP-TO- 
SHORE 
OR "CB" 
MIKE! 

o $9.95 



Terms: add postage Rated: net HO 
Phone Orders: Wakefield, Ma^. <6lTj 245-382! 
Retatlt 16-18 Del Carmine St., Wakefield. Mass. 
(off Water Street) C.O.D-'S MAY BE PHONED 

. 20c CATALOG Fiber Optics. *ICs\ Semi's, Parts 
MINIMUM ORDER S4.00 



BOX 942A LYNNFIELD.MASS. 01940 



READER SERVICE 

Check appropriate boxes for desired company 
brochures, data sheets or catalogs and mail in to 
73. Include your zip code, please. Send money 
directly to advertisers. 

LIMIT: 25 requests. 



ADVERTISER INDEX 



□ ADVA 53 

p Airwaves Elect 84 

* ATV 1 1 2 

OA&W Elect 146. 147 
n Babylon 151 

O Columbia 118 
pComcraft 88 
u Comm. Spec 112 
aComm. Unlimited 154 
O Cornell 40 

* Cubex 44 

a Data Eng 70 r 120 
n Dupage 1 44 

* Dynamic Elec 110 
OECM 110 

a Emergency Beacon 18 19 
a Erickson 1 25 
DFreck 84 
D Gateway 66 
D GEN AVE 57 

□ God bout 155 
aHaband CIV 

uHAL 71 

i i Ham Radio Center 148 

a Henry 7, 73 

i iHumcun Digital 35 

□ ICOM 157 

a inter Elect 150 

□ Inter Telecomm 35 
DJatnes Elec 76 



a Jan 1 03 

Q Juge 1 45 
OKA 143 

n Meshna 158 

Q Morgain 40 

D NewTronics CI I 

D PaJomar 62 

Q Poly Paks 159 

O Quement 62 

O Radio Amateur Call book 87 

D Regency 1 5 

a RGS 1 52 

a SceJbi 110 

u Selec ironies 142 

O Sentry 1 1 

D Solid State 153 

O Solid State Surplus 149 

O Space Elect 40 

□ Spectrum Comm CI 1 1 
D SST Elec 1 35 

p Stabler 1 1 2 
a Standard 63 

□ TPL 93 

q Tri Tek 48 

O Tucker 22 f 23 

D VHP Eng 156 

a Wideband Eng 84 

p Wolf 110 

C3 World GSL 110 

□ Yaesu 68 



73 STUFF 

Digital Control 60 

QSLs 97 

73 Code Courses 101 

Books 105 

Subs 109 

Novice Guide 112 

Repeater Atlas 118 

Hot Line 122 

Novice Tapes 122 

73 Recorders 1 29 



D NEWSSTAND 



Q SUBSCRIPTION 



* Reader service inquiries not solicited. Correspond 
directly to company. 

OCTOBER 1974 

Reader's Service 
73 inc., Peterborough NH 03458 

Please Print or Type 



Name 



Call 



Address 



City 



State 



Zip 



PROPAGATION CHART 

J.H. Nelson 

Good (open) Fair (a) Poor (O) 



*974 




s 



;t n 



M 



Off 



Tin If hi Thu 



r/ 



Sat 



6 



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8 



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2 E 





© © 



20 21 




© m 





IO II 12 



17 i 



8 







EASTERN UNITED STATES TO: 



Coupon expires in 60 days . * . * , 



GMT: 


00 


tn 


04 


06 


08 


10 


12 


14 


n 


IS 


20 


22 




ALASKA 


14 


i 


7 


7 


2 


: 


3 


7 7 


14 


14 


14 




ARGENTINA 


14 


to 


it 


70 


1 


7 


14 


» 


31 


21 


21 


21 




AUSTRALIA 


14 


n 


m 


7B 


76 ' 


7B 


7B 


14 


140 


146 


14 


21 




CANAL ZONE 


14 


j 


7 


7 


7 


7 


14 


14A 


21 


21 


21 


I4A 




ENGLAND 


7 


7 


3 


3 


? 


' 


14 


tJA 


14A 


14 


14 


' 




HAWAII 


14 


7B 


7B 


7 


7 


: 


7 


7B 


I4B 14 


I4A 


14A 




INDIA 


7 


7 


7B 


?& 


7B 


?B 


14 


14 


7B 


78 


7 


7 




JAPAN 


M 


m 


m 


70 


7 


7 


7 


7 


7 


7B 


7B 


14 




MEXICO 


14 


f 


r 


7 


7 


7 


7 


14 


14 


14 


T4A 


14 .-. 




PHILIPPINES 


14 


7B 


7B 


7B 


7B 


7B 


7 


7A 


f 


76 


7B 


ffl 




PUERTO RICO 


7 


7 


7 


. e 


3A 


3A 


14 


14 


14 


14 


14A 


14 




SOUTH AFRICA 


1 


7 


7 


7 


7G 


14 


Si 


21 


7: 


L'l 


14A 


14 




U. S S R, 


7 


2 


3 


3 


7 


;r 


14 


14 


14 


146 


7D 


* 




WEST COAST 


14 


1 


t 


7 


7 


3A 


7 


14 


14 14 


I4A 


21 












S TO: 




CENTRAL UP 


JITEl 


3 STATE: 




ALASKA 


14 


tT 7 | 7 


3 


3 


3 ; 1 


7 


ft 


14 


14 




ARGENTINA 


(4 


76 


m 


tv. 


7 


7 


76 


14 


21 


21 


21 


?1 




AUSTRALIA 


71 


14 


71 


70 


70 


7B 


7B 


7 


l4h 


I4h 


14 


L'l 




CANAL ZONE 


14 


7 


7 


7 


} 


7 


7 


14 A 


21 


21 


21 


31 




ENGLAND 


" 


7 


3 


3 


7 


3 


7B 


14 


14 


14 


14 


7 




HAWAII 


14A 


:,! 


7 


7 


7 


7 


' 


7 


14Q 


14A 


?T 


2t 




INDIA 


I 


tti 


78 


7B 


7B 


3B 


-." 


7 


7 A 


7 


7 


7 




JAPAN 


14 


I4f 


?B 


7B 


JA 


' 


3 


7 


7 


7fl 


72 


14 




MEXICO 


14 


) 


7 


1 


7 


3 


7 


7A 


14 


14 


14 


14 




PHILIPPINES 


14 


14 


7B 


70 


3S 


7 * 


39 


7 


7 


7 


Ft 


14 




PUERTO RICO 


14 


7 


7 


J 


7 


7 


7A 


14 


14 A 


14* 


21 


I4A 




SOUTH AFRICA 


7 


7 


7 




7B 


7B 


14 


14 


14 


T4A 


!4m 


14 




U. S. S R 


? 


3 




7 


3A 


76 


14 


14 




7B 





WESTERN UNITED STATES TO: 


ALASKA 


14} 


7A 


7 


? 


3 


3 


3 


7 


T 


7A 


14 


,. 


ARGENTINA 


14 


14 


76 


76 


7 


7 


7B 


14 


21 


31 


21 


2t 


AUSTRALIA 


21 


21 


14 


76 


76 


?B 


Tfi 


I 


T 


JB 


14 


21 


CANAL ZONE 


14 


7A 


7 


7 


J 


7 


7 


14 


21 


21 


31 


21 


ENGLAND 


7 


7 


- 


3 


7 


: 


36 


7 


14 


14 


14B 


^ 


HAWAII 




14 




7 


7 


7 


J 


7A 


t4A 


21 


» 


INDIA 


7 4 


tu 


7B 


IF 


3B 


3B 


' 


7 


7 


7 


7 


JAPAN 


:* 


14 


UK 


7B 


3* 


7 


7 


7 


J 


76 


14R 


14 


MEXICO 


■ 4 


T4B 


7 




7 


7 


7 


7A 


14 


14 


4 . 


'4.. 


PHILIPPINES 


14 


14 


14 


T6 


76 


7S 


7 


" 


1 


IS 


14 


PUERTO RICO 


|4 


7 




7 


7 


7 


7 


14 


14 


I4A 


21 


-' < 


SOUTH AFRICA 


7B 


7 


7 


7 


73 


7B 


7B 


14 


14 


14 


I4A 


14 


USSR. 


7 


3 


3 


ji 


3 


3 


3 


7 


7A 


F4 


I 


m 


EAST COAST 


14 


7 


■* 


7 




3A 


7 


14 


14 114 |14A ?1 



A = Next higher frequency may be useful also, 
B = Difficult circuit this period. 



160 



73 MAGAZINE 



MkJJ M ENGINEERING BREAKTHROUGH! 

^ J£** A OSPEC COA1/M KN ° CKS ™ E W ' ND 
^sflf tH -ce a t /b --* *- U/V,/VI OUT OF INFLATION 

^AT^ ^iirfA^ nOlC*^ 1 



$ 






^JS?V^0L 



*» 



«&»»* 



;**** 

^ ,^' 



^ 




OPTIONAL ACCESSORIES COMING SOON 
d **CIip-on" rechargable battery module, 
wj carrying strap & 1 8" antenna. 

o "Clip-on" 25 watt amplifier flo noise 
receiver preamp module. 

Q "Clip-on" A. C. Power supply module. 

° Switchable 6 channel xtal deck to 
expand radio to 12 channels. 

□ Companion Synthesizer 

LOW INTRODUCTORY PRICE! 



$139.95 



MADE IN USA 

90 DAY WARRANTY 



(FULLY WIRED & TESTED - NOT A KIT) 



(PRICE FIRM ON ALL ORDERS POSTMARKED ON OR BEFORE NOV. 15, 1 974} 






Engineered to provide the best possible perfor- 
mance at the lowest possible price, the SpecComm 
560 opens the world of 2 Meter FM to every one- 
Integrated circuitry is used to the greatest possible 
extent for top performance and reliability, along with 
other *State of the Art' circuit techniques which are 
now practical at low cost. The receiver features a very 
wide dynamic range front end which provides 
excellent intermod and overload performance. This is 
followed by a six pole monolithic crystal filter for 
superior adjacent channel rejection. (Not a less selec- 
tive four pole filter used in many more expensive 
units). 

The transmitter features a low distortion phase 
modulator combined with excellent speech processing 
for beautiful sounding audio with 'plenty of punch- 1 
The final stage uses a fully VSWR protected transistor, 
thus eliminating the nuisance and expense of critical 
shutdown circuitry, 

A complete complement of accessories will be 
available so that the unit may be operated over the 
shoulder, mobile or fixed. Compact, clip-on modules 
are an integral part of the radio - not an afterthought! 
Another Plus - the SpecComm 560 uses commonly 
available, low cost, TR22 type crystals. 

Order your SPEC COM 560 today . . . direct From the 
factory at the low introductory price of $139.95 w/l 
set xtals (.52 or .94 simplex — specify first choice) 



Mobile Mounting Bracket 
Include Postage and Handling 
(PA residents add 6% tax) 



$6.95 

$200 



D 



n Bandwidth 



Front End 



n 



□ 



□ 

D 
D 
D 

D 



□ Squelch 



Sensitivity O.^UV (typ.) 20dB 

quieting 
■ ±7,5 kHz @ -6dB 
±20 kHz @ -60dB 
• FET w/Wide Dynamic 
Range Mixer for 
very low I.M. 

I-F 10.7 MHz, single 

conversion 
- Fast attack; noise 
operated 
l=l Audio Output . . 2 wts (nom.l, 

3 -8 Q Speaker 

. 5 wts (typ J 
@12.5 VDC 

. Low distortion 
Phase Modulator, w/ 
up to 1 2dB of 
Speech Clipping 

Deviation Adjustable; factory 

set to ±5 kHz 

Fully VSWR protected 

No shutdown required 

. Hi Z Ceramic, 
(Turner) 

Frequency Range . , , 146 to 148 MHz 
6 Channels w/trimmer caps on all xtals 
Reverse Polarity protected 
Built-in speaker 
Electronic T/R switching — 

No relay problems 



Q Power Output 
O Modulation . . 



O Final Stage . 
Microphone 



Send Card for Spec Sheet. 



SPECTRUM COMMUNICATIONS 



P.O. BOX 140 




WORCESTER, PA 19490 

215-584-6469 



— 



Easy Care 
NO IRON 

NON-SNAG 




35 Minute Wash & Wear 




i 






Order Direct by Mail! 

HABAND 1 " SoVTPoly este r 

KNITS 



i 
i 

i 
i 



Note aft the 

FINE 
TAILORING 

that KEEPS 
the GOOD 
LOOKS! 



FIND YOUR WAIST & INSEAM HERE 



Waists: 29-3CM 1-32-33-34-35-36-37- 
38-39-40-41-42-43-44^5-46- 
47-48-49-50-51 -52 -5:i-:> I 

Inseams: 26-27-28-29-30-31-32-3 3-34 



HABAND COMPANY, 265 North 9th St.. 
Paterson, New Jersey 07508 

Gentlemen: Ptfaf* ftufa me pair?; of 

thr>r polvr>trr Knit Shrk>. for which I enclose 
S remittance m full. 



■ ■ ■" 1 1 ■ * * ■ * 



i 
i 
i 
i 
i 
i 
i 
i 

i 
i 
i 



COLOR 



GOLD 



NAVY 



BROWN 



w*m 



iniiim 



Spec tat Prtces: 
3 pairs $29,70 
(i . 4 for 39.20 5 for 48.75 

wuaranlpf „ for anv r03son fdonol 

choose to wear the stacks after f have seen and 
xned them on, f may return them for futt refund 
of every penny / paid you. 

865-04 



(Please Print) 



Strrrl 



Cm 



ZIP 
Sfalf CODE 



COLOR 



GREEN 



Burgundy 



pairs 

for 

only 



And take a good kick at Inflation!' 

Fven though the price of lOOT Pol\ t-vter hjs morel 
than doubled in the last 12 months (polyester 
is j petroleum derh ative), Haband has you 
protected for this one last 2 for $19.95 offer. 

Deluxe Executive Knit Slacks! I 

A You nave seen 100% Polyester kmts for overl 
,\ $20 a pair* This year you'll see them for even I 
more, and wonder who's got the money to j 
afford them. These Haband Siactcs might 
be the answer. They always look fresn, 
never neerj ironing. The heavy two-way 
knit means two-way fit, and tnat 
means Double Value. More comfortable I 
full fit in seat, crotch, and thighs but, 
also a trim straight look that never 
is or droops. 

MACHINE WASHABLE I 

tensions or tight spots. No 
Iron. No Dry Hearing. A simplJ 
spin through the home wash 
machine js all they need. What 
you get is rop value Two-Waj i 
Knit Slacks and FREE 
COMFORT LIKE YOU 
& NEVER FELT BEFORE! | 
Remember, 8u$mess Stack st 
are Haband s Business. 
m Our experience oositive| 
ly shouts that knits are I 
your best buy. Now ( 
our tremendous 
inventory carry-' 
over makes thus 
one last market ' 
scoop st III 
possible: 

2Mtri 
Qfll r 

19.95 

But please! 

Knits arel 
in hugei 
demand) 




I 



100% Polyester 
NON-SNAG Knit 

Ban-Rol®' 
No Roll 
Inner Waistband 

• No Pucker 
Flat Ffy 

• New Unbreakable 

Nylon Spiral Zipper 

New Long-Wearing 
No-Hole" Knit Pockets 

Wtde Sett Loops for 
Today's Wider 8efts. 

• Hook Top Closure 

• Modified Flare 
Bottoms 

Automatic Machine 

wash & wear; 

NO IRONING EVER! 

*FAST RELIABLE 
SERVICE 1 



265 North 9th Street, Paterson, NJ 07508 

A conscientious f amity Business, established 1925 



I 

I 
I